NEWS

Polars R Package (development version)

Polars R Package 0.21.0

Breaking changes

Updated Rust Polars to 0.44.2 (#1271).
- Minimum supported Rust version (MSRV) is now 1.82.0.
- $reshape()'s nested_type argument is removed.
- $approx_n_unique() no longer works on Categorical type.
<Series>$compare() is removed. (#1272)

Deprecations

Passing a single data.frame to pl$DataFrame() or pl$LazyFrame() to convert a data.frame to a polars DataFrame or LazyFrame is deprecated and a warning will be shown. Use as_polars_df() or as_polars_lf() instead (#1275).

Bug fixes

Maintain level order when converting Enums to factors (#1252, @andyquinterom).

Polars R Package 0.20.0

Updated Rust Polars to 0.43.1 (#1230).

Breaking changes

In pl$scan_ipc() and pl$read_ipc(), the argument memory_map is removed (#1230).
In $serialize(), in the field schema, the field inner is renamed fields, and the fields output_schema and filter are removed (#1230).

New features

New method $cast() for DataFrame and LazyFrame (#1219).
New argument strict in $drop() to determine whether unknown column names should trigger an error (#1220).
New method $to_dummies() for DataFrame (#1225).
New argument include_file_paths in pl_scan_csv() and pl_read_csv() (#1235).
New method $join_where() for DataFrame and LazyFrame to perform inequality joins (#1237).

Bug fixes

Converting data of datatype Null to R doesn't error anymore. It now creates a column filled with NA (#1217).

Polars R Package 0.19.1

This is a maintenance release. No user facing changes.

Polars R Package 0.19.0

Breaking changes

Updated Rust Polars to unreleased 2024-08-20, after 0.42.0 (#1183).
$describe_plan() and $describe_optimized_plan() are removed. Use respectively $explain(optimized = FALSE) and $explain() instead (#1182).
The parameter inherit_optimization is removed from all functions that had it (#1183).
In $write_parquet() and $sink_parquet(), the parameter data_pagesize_limit is renamed data_page_size (#1183).
The LazyFrame method $get_optimization_toggle() is removed, and $set_optimization_toggle() is renamed $optimization_toggle() (#1183).
In $unpivot(), the parameter streamable is removed (#1183).
Some functions have a parameter future that determines the compatibility level when exporting Polars' internal data structures. This parameter is renamed compat_level, which takes FALSE for the oldest flavor (more compatible) and TRUE for the newest one (less compatible). It can also take an integer determining a specific compatibility level when more are added in the future. For now, future = FALSE can be replaced by compat_level = FALSE (#1183).
In $scan_parquet() and $read_parquet(), the default value of hive_partitioning is now NULL (#1189).
In $dt$epoch(), the argument tu is renamed to time_unit (#1196).
In $fill_nan() for DataFrame, LazyFrame and Expr, the argument is renamed value (#1198).
$shift_and_fill() is removed and replaced by a new argument fill_value in $shift(). $shift_and_fill(fill_value, periods) can be replaced by $shift(n, fill_value) (#1201).
In $shift() for various Expr, the argument periods is renamed n (#1201).
In $clip(), arguments min and max are renamed lower_bound and upper_bound (#1203).
$clip_min() and $clip_max() are removed. Use $clip() with only lower_bound or upper_bound instead (#1203).
In $write_csv and $sink_csv(), the argument quote is renamed quote_char (#1206).

New features

New method $str$extract_many() (#1163).
Converting a nanoarrow_array with zero rows to an RPolarsDataFrame via as_polars_df() now keeps the original schema (#1177).
$write_parquet() has two new arguments partition_by and partition_chunk_size_bytes to write a DataFrame to a hive-partitioned directory (#1183).
New method $bin$size() (#1183).
In $scan_parquet() and $read_parquet(), the parallel argument can take the new value "prefiltered" (#1183).
$scan_parquet(), $scan_ipc() and $read_parquet() have a new argument include_file_paths to automatically add a column containing the path to the source file(s) (#1183).
$scan_ipc() can read a hive-partitioned directory with its new arguments hive_partitioning, hive_schema, and try_parse_hive_dates (#1183).
$scan_parquet() and $read_parquet() gain two new arguments for more control on importing hive partitions: hive_schema and try_parse_hive_dates (#1189).
New method $gather_every() for LazyFrame and DataFrame (#1199).
$glimpse() for DataFrame has two new arguments max_items_per_column and max_colname_length (#1200).
New method $list$sample() (#1204).
New argument coalesce in $join_asof() (#1205).
New argument maintain_order in $list$unique() (#1207).

Other changes

In $unnest() for DataFrame and LazyFrame, the names argument is removed and replaced by .... This doesn't change the previous behavior, e.g. df$unnest(names = c("a", "b")) still works (#1170).

Polars R Package 0.18.0

Breaking changes

Updated Rust Polars to 0.41.3 (#1147, #1156).
In $n_chunks(), the default value of strategy now is "first" (#1137).
$sample() for Expr and DataFrame (#1136):
- the argument frac is renamed fraction;
- all the arguments except n must be named;
- for the Expr method only, the first argument is now n (it was already the case for the DataFrame method);
- for the Expr method only, the default value for with_replacement is now FALSE (it was already the case for the DataFrame method).
$melt() had several changes (#1147):
- melt() is renamed $unpivot().
- Some arguments were renamed: id_vars is now index, value_vars is now on.
- The order of arguments has changed: on is now first, then index. The order of the other arguments hasn't changed. Note that on can be unnamed but all the other arguments must be named.
pivot() had several changes (#1147):
- The argument columns is renamed on.
- The order of arguments has changed: on is now first, then index and values. The order of the other arguments hasn't changed. Note that on can be unnamed but all the other arguments must be named.
In $write_parquet() and $sink_parquet(), the default value of argument statistics is now TRUE and can take other values than TRUE/FALSE (#1147).
In $dt$truncate() and $dt$round(), the argument offset has been removed. Use $dt$offset_by() after those functions instead (#1147).
In $top_k() and $bottom_k() for Expr, the arguments nulls_last, maintain_order and multithreaded have been removed. If any null values are in the top/bottom k values, they will always be positioned last (#1147).
$replace() has been split in two functions depending on the desired behaviour (#1147):
- $replace() recodes some values in the column, leaving all other values unchanged. Compared to the previous version, it doesn't use the arguments default and return_dtype anymore.
- $replace_strict() replaces all values by different values. If a value doesn't have a specific mapping, it is replaced by the default value.
$str$concat() is deprecated, use $str$join() (with the same arguments) instead (#1147).
In pl$date_range() and pl$date_ranges(), the arguments time_unit and time_zone have been removed. They were deprecated in previous versions (#1147).
In $join(), when how = "cross", on, left_on and right_on must be NULL (#1147).

New features

New method $has_nulls() (#1133).
New method $list$explode() (#1139).
$over() gains a new argument order_by to specify the order of values within each group. This is useful when the operation depends on the order of values, such as $shift() (#1147).
$value_counts() gains an argument normalize to give relative frequencies of unique values instead of their count (#1147).

Polars R Package 0.17.0

Breaking changes

Updated Rust Polars to unreleased version (> 0.40.0) (#1104, #1110, #1117, #1124):
- In $join(), there is a new argument coalesce and the how options now accept "full" instead of "outer" and "outer_coalesce".
- $top_k() and $bottom_k() gain three arguments nulls_last, maintain_order and multithreaded.
- All $rolling_*() functions lose the arguments by, closed and warn_if_unsorted. Rolling computations based on by must be made via the corresponding rolling_*_by(), e.g rolling_mean_by() instead of rolling_mean(by =) (#1115).
- pl$scan_parquet() and pl$read_parquet() gain an argument glob which defaults to TRUE. Set it to FALSE to avoid considering * as a globing pattern.
- $is_not_nan() on a null value (NA in R) now returns null. Previously, it returned TRUE.
- In $reshape(), argument dims is renamed dimensions and there is a new argument nested_type specifying if the output should be of type List or Array.
- In $value_counts(), all arguments must be named and there is a new argument name to specify the name of the output.
- In all functions accepting optimization parameter (such as projection_pushdown), there is a new parameter cluster_with_columns to combine sequential independent calls to $with_columns().
- $str$explode() is removed.
- The check_sorted argument is removed from $rolling() and $group_by_dynamic(). Sortedness is now verified in a quick manner, so this argument is no longer needed (pola-rs/polars#16494).
- $name$map() stacks on Linux, so this method is deprecated and the document is removed. Please use other methods like <LazyFrame>$rename(<function>) instead (#1123).
As warned in v0.16.0, the order of arguments in pl$Series is changed (#1071). The first argument is now name, and the second argument is values.
$to_struct() on an Expr is removed. This method is now only available for Series, DataFrame, and in the $list and $arr subnamespaces. For example, pl$col("a", "b", "c")$to_struct() should be replaced with pl$struct(c("a", "b", "c")) (#1092).
pl$Struct() now only accepts named inputs and objects of class RPolarsField. For example, pl$Struct(pl$Boolean) doesn't work anymore and should be named like pl$Struct(a = pl$Boolean) (#1053).
In $all() and $any(), the argument drop_nulls is renamed ignore_nulls, and this argument must be named (#1050).
New method $struct$with_fields() (#1109) and new function pl$field() to be used in expressions in $struct$with_fields() (#1113).
New methods for RPolarsDataType: $is_enum(), $is_categorical(), $is_known(), $is_string(), $contains_views(), $contains_categorical() (#1112).
In $dt$combine(), the arguments tm and tu are renamed time and time_unit (#1116).
The default value of the rechunk argument of pl$concat() is changed from TRUE to FALSE (#1125).
In $rename() for LazyFrame and DataFrame, key-value pairs of names are changed to old_name = "new_name" instead of new_name = "old_name" (#1129).
In $rename() for LazyFrame and DataFrame, no argument is not allowed (#1129).
In all $rolling_*() functions, the arguments center and ddof must be named (#1115).

New features

Allow specify a function in $rename() for LazyFrame and DataFrame. They are equivalent to polars.LazyFrame.rename(mapping: Callable[[str], str]) or polars.DataFrame.rename(mapping: Callable[[str], str]) in Python Polars (#1122, #1129).

Polars R Package 0.16.4

New features

pl$read_ipc() can read a raw vector of Apache Arrow IPC file (#1072).
New method <DataFrame>$to_raw_ipc() to serialize a DataFrame to a raw vector of Apache Arrow IPC file format (#1072).
New method <LazyFrame>$serialize() to serialize a LazyFrame to a character vector of JSON representation (#1073).
New function pl$deserialize_lf() to deserialize a LazyFrame from a character vector of JSON representation (#1073).
New methods $str$head() and $str$tail() (#1074).
New S3 methods nanoarrow::as_nanoarrow_array_stream() and nanoarrow::infer_nanoarrow_schema() for RPolarsSeries (#1076).
New method $dt$is_leap_year() (#1077).
as_polars_df() and as_polars_series() supports arrow::RecordBatchReader (#1078).
The new experimental argument for as_polars_df(<ArrowTabular>), as_polars_df(<RecordBatchReader>), as_polars_series(<nanoarrow_array_stream>), and as_polars_df(<nanoarrow_array_stream>) (#1078). If experimental = TRUE, these functions switch to use the Arrow C stream interface internally. At this point, the performance is degraded under the expected use cases, so the default is set to experimental = FALSE.

Polars R Package 0.16.3

New features

New method <SQLContext>$register_globals() (#1064).
New experimental method $sql() for DataFrame and LazyFrame (#1065).

Miscellaneous

Move the API document website to the new place (#1067, #1068). Access to the old website is set to redirect to the top page of the new website.
- Old URL: https://rpolars.github.io/
- New URL: https://pola-rs.github.io/r-polars/

Polars R Package 0.16.2

New features

$cut() and $qcut() to bin continuous values into discrete categories (#1057).
pl$scan_parquet() and pl$read_parquet() can read data from the internet by specifying a URL to the first argument (#1056, @andyquinterom).
pl$scan_parquet() and pl$read_parquet() gain an argument storage_options to scan/read data via cloud storage providers (GCP, AWS, Azure). Note that this support is experimental (#1056, @andyquinterom).
Add support for the Enum datatype via pl$Enum() (#1061).

Bug fixes

In some read/scan functions, downloading files could fail if the URL was too long. This is now fixed (#1049, @DyfanJones).

Polars R Package 0.16.1

This is a small hot-fix release to update dependent Rust Polars to 0.39.1 (#1042).

Also, there are some updates.

Bug fixes

$len() now correctly includes null values in the count (#1044).

Other improvements

$arr$max() and $arr$min() work without the nightly feature (#1042).

Polars R Package 0.16.0

Breaking changes

Rust Polars is updated to 0.39.0 (#937, #1034).

R objects inside an R list are now converted to Polars data types via as_polars_series() (#1021, #1022, #1023). For example, up to polars 0.15.1, a list containing a data.frame with a column of {clock} naive-time class was converted to a nested List type of Float64:

data = data.frame(time = clock::naive_time_parse("1990-01-01", precision = "day"))
pl$select(
  nested_data = pl$lit(list(data))
)
#> shape: (1, 1)
#> ┌──────────────────────────┐
#> │ nested_data              │
#> │ ---                      │
#> │ list[list[list[f64]]]    │
#> ╞══════════════════════════╡
#> │ [[[2.1475e9], [7305.0]]] │
#> └──────────────────────────┘

From 0.16.0, nested types are correctly converted, so that will be a List type of Struct type containing a Datetime type.

data = data.frame(time = clock::naive_time_parse("1990-01-01", precision = "day"))
pl$select(
  nested_data = pl$lit(list(data))
)
#> shape: (1, 1)
#> ┌─────────────────────────┐
#> │ nested_data             │
#> │ ---                     │
#> │ list[struct[1]]         │
#> ╞═════════════════════════╡
#> │ [{1990-01-01 00:00:00}] │
#> └─────────────────────────┘

Several functions have been rewritten to match the behavior of Python Polars. There are four types of changes: a) change in argument names, b) change in the way arguments are passed (named or by position), c) arguments are removed, and d) change in the default and accepted values. Those are addressed separately below.
1. Change in argument names:
  - In $reshape(), the dims argument is renamed to dimensions (#1019).
  - In pl$read_* and pl$scan_* functions, the first argument is now source (#935).
  - In pl$Series(), the argument x is renamed values (#933).
  - In <DataFrame>$write_* functions, the first argument is now file (#935).
  - In <LazyFrame>$sink_* functions, the first argument is now path (#935).
  - In <LazyFrame>$sink_ipc(), the argument memmap is renamed to memory_map (#1032).
  - In <DataFrame>$rolling(), <LazyFrame>$rolling(), <DataFrame>$group_by_dynamic() and <LazyFrame>$group_by_dynamic(), the by argument is renamed to group_by (#983).
  - In $dt$convert_time_zone() and $dt$replace_time_zone(), the tz argument is renamed to time_zone (#944).
  - In $str$strptime(), the argument datatype is renamed to dtype (#939).
  - In $str$to_integer() (renamed from $str$parse_int()), argument radix is renamed to base (#1038).
2. Change in the way arguments are passed:
  - In all input/output functions, all arguments except the first argument must be named arguments (#935).
  - In <DataFrame>$rolling() and <DataFrame>$group_by_dynamic(), all arguments except index_column must be named arguments (#983).
  - In $unique() for DataFrame and LazyFrame, arguments keep and maintain_order must be named (#953).
  - In $bin$decode(), the strict argument must be a named argument (#980).
  - In $dt$replace_time_zone(), all arguments except time_zone must be named arguments (#944).
  - In $str$contains(), the arguments literal and strict must be named (#982).
  - In $str$contains_any(), the ascii_case_insensitive argument must be named (#986).
  - In $str$count_matches(), $str$replace() and $str$replace_all(), the literal argument must be named (#987).
  - In $str$strptime(), $str$to_date(), $str$to_datetime(), and $str$to_time(), all arguments (except the first one) must be named (#939).
  - In $str$to_integer() (renamed from $str$parse_int()), all arguments must be named (#1038).
  - In pl$date_range(), the arguments closed, time_unit, and time_zone must be named (#950).
  - In $set_sorted() and $sort_by(), argument descending must be named (#1034).
  - In pl$Series(), using positional arguments throws a warning, since the argument positions will be changed in the future (#966).
```
# polars 0.15.1 or earlier
# The first argument is `x`, the second argument is `name`.
pl$Series(1:3, "foo")

# The code above will warn in 0.16.0
# Use named arguments to silence the warning.
pl$Series(values = 1:3, name = "foo")
pl$Series(name = "foo", values = 1:3)

# polars 0.17.0 or later (future version)
# The first argument is `name`, the second argument is `values`.
pl$Series("foo", 1:3)
```
    This warning can also be silenced by replacing pl$Series(<values>, <name>) by as_polars_series(<values>, <name>).
3. Arguments removed:
  - The argument columns in $drop() is removed. $drop() now accepts several character scalars, such as $drop("a", "b", "c") (#912).
  - In pl$col(), the name argument is removed, and the ... argument no longer accepts a list of characters and RPolarsSeries class objects (#923).
  - In pl$date_range(), the unused argument (not working in recent versions) explode is removed. (#950).
4. Change in arguments default and accepted values:
  - In pl$Series(), the argument values has a new default value NULL (#966).
  - In $unique() for DataFrame and LazyFrame, argument keep has a new default value "any" (#953).
  - In rolling aggregation functions (such as $rolling_mean()), the default value of argument closed now is NULL. Using closed with a fixed window_size now throws an error (#937).
  - In pl$date_range(), the argument end must be specified and the default value of interval is changed to "1d". The arguments start and end no longer accept numeric values (#950).
  - In pl$scan_parquet(), the default value of the argument rechunk is changed from TRUE to FALSE (#1033).
  - In pl$scan_parquet() and pl$read_parquet(), the argument parallel only accepts "auto", "columns", "row_groups", and "none". Previously, it also accepted upper-case notation of "auto", "columns", "none", and "RowGroups" instead of "row_groups" (#1033).
  - In $str$to_integer() (renamed from $str$parse_int()), the default value of base is changed from 2 to 10 (#1038).

The usage of pl$date_range() to create a range of Datetime data type is deprecated. pl$date_range() will always create a range of Date data type in the future. Use pl$datetime_range() if you want to create a range of Datetime instead (#950).
<DataFrame>$get_columns() now returns an unnamed list instead of a named list (#991).
Removed $argsort() which was an old alias for $arg_sort() (#930).
Removed pl$expr_to_r() which was an alias for $to_r() (#938).
<Series>$to_r_list() is renamed <Series>$to_list() (#938).
Removed <Series>$to_r_vector() which was an old alias for <Series>$to_vector() (#938).
Removed <Expr>$rep_extend(), which was an experimental method created at the early stage of this package and does not exist in other language APIs (#1028).
The following deprecated functions are now removed: pl$threadpool_size(), <DataFrame>$with_row_count(), <LazyFrame>$with_row_count() (#965).
In $group_by_dynamic(), the first datapoint is always preserved (#1034).
$str$parse_int() is renamed to $str$to_integer() (#1038).

New features

New functions:
- pl$arg_sort_by() (#929).
- pl$arg_where() to get the indices that match a condition (#922).
- pl$datetime(), pl$date(), and pl$time() to easily create Expr of class datetime, date, and time via columns and literals (#918).
- pl$datetime_range(), pl$date_ranges() and pl$datetime_ranges() (#950, #962).
- pl$int_range() and pl$int_ranges() (#968)
- pl$mean_horizontal() (#959)
- pl$read_ipc() (#1033).
- is_polars_dtype() (#927).

New methods:
- <LazyFrame>$to_dot() to print the query plan of a LazyFrame with graphviz dot syntax (#928).
- $clear() for DataFrame, LazyFrame, and Series (#1004).
- $item() for DataFrame and Series (#992).
- $select_seq() and $with_columns_seq() for DataFrame and LazyFrame (#1003).
- $arr$to_list() (#1018).
- $str$extract_groups() (#979).
- $str$find() (#985).
- <DataFrame>$write_ipc() (#1032).
- RPolarsDataType gains several methods to check the datatype, such as $is_integer(), $is_null() or $is_list() (#1036).

New arguments or argument values:
- ambiguous can now take the value "null" to convert ambigous datetimes to null values (#937).
- n in $str$replace() (#987).
- non_existent in $dt$replace_time_zone() to specify what should happen when a datetime doesn't exist.
- mapping_strategy in $over() (#984, #988).
- raise_if_undetermined in $meta$output_name() (#961).
- null_on_oob in $arr$get() and $list$get() to determine what happens when the index is out of bounds (#1034).
- nulls_last, multithreaded, and maintain_order in $sort_by() (#1034).

Other:
- pl$Series() now calls as_polars_series() internally, so it can convert more classes to Series properly (#1015).
- Export the Duration datatype (#955).
- New active binding <Series>$struct$fields (#1002).
- All $write_*() and $sink_*() functions now invisibly return the input data (#1039).

Bug fixes

The join_nulls and validate arguments of <DataFrame>$join() now work correctly (#945).
We said in the changelog of 0.14.0 that all row_count_* args in I/O functions were renamed row_index_*, but this change was not made for CSV and IPC functions. This renaming is now made (#964).
Evaluating Series methods from Expr inside functions now works correctly (#973). Thanks @Yunuuuu for the report.
The dependent crate extendr-api is updated to 2024-03-31 unreleased version (#995). The issue that the R session crashes when a panic occurs in the Rust side is resolved. Thanks @CGMossa for the upstream fix.
The parallel argument of pl$scan_parquet() and pl$read_parquet() now works correctly (#1033). Previously, any correct value was treated as "auto".

Polars R Package 0.15.1

New features

Rust Polars is updated to 0.38.2 (#907).
- Minimum supported Rust version (MSRV) is now 1.76.0.
as_polars_df(<nanoarrow_array>) is added (#893).
It is now possible to create an empty DataFrame with a specific schema with pl$DataFrame(schema = my_schema) (#901).
New arguments dtype and nan_to_null for pl$Series() (#902).
New method <DataFrame>$partition_by() (#898).

Bug fixes

The default value of the format of $str$strptime() is now correctly set (#892).

Other improvements

Performance of as_polars_df(<nanoarrow_array_stream>) is improved (#896).

Polars R Package 0.15.0

Breaking changes due to Rust Polars update

Rust Polars is updated to 0.38.1 (#865, #872).
- in $pivot(), arguments aggregate_function, maintain_order, sort_columns and separator must be named. Values that are passed by position are ignored.
- in $describe(), the name of the first column changed from "describe" to "statistic".
- $mod() methods and %% works correctly to guarantee x == (x %% y) + y * (x %/% y).

Other breaking changes

Removed as.list() for class RPolarsExpr as it is a simple wrapper around list() (#843).
Several functions have been rewritten to match the behavior of Python Polars.
- pl$col(...) requires at least one argument. (#852)
- pl$head(), pl$tail(), pl$count(), pl$first(), pl$last(), pl$max(), pl$min(), pl$mean(), pl$media(), pl$std(), pl$sum(), pl$var(), pl$n_unique(), and pl$approx_n_unique() are syntactic sugar for pl$col(...)$<method()>. The argument ... now only accepts characters, that are either column names or regular expressions (#852).
- There is no argument for pl$len(). If you want to measure the length of specific columns, you should use pl$count(...) (#852).
- <Expr>$str$concat() method's delimiter argument's default value is changed from "-" to "" (#853).
- <Expr>$str$concat() method's ignore_nulls argument must be a named argument (#853).
- pl$Datetime()'s arguments are renamed: tu to time_unit, and tz to time_zone (#887).
pl$Categorical() has been improved to allow specifying the ordering type (either lexical or physical). This also means that calling pl$Categorical doesn't create a DataType anymore. All calls to pl$Categorical must be replaced by pl$Categorical() (#860).
<Series>$rem() is removed. Use <Series>$mod() instead (#886).

The conversion strategy between the POSIXct type without time zone attribute and Polars datetime has been changed (#878). POSIXct class vectors without a time zone attribute have UTC time internally and is displayed based on the system's time zone. Previous versions of polars only considered the internal value and interpreted it as UTC time, so the time displayed as POSIXct and in Polars was different.

# polars 0.14.1
Sys.setenv(TZ = "Europe/Paris")
datetime = as.POSIXct("1900-01-01")
datetime
#> [1] "1900-01-01 PMT"

s = polars::as_polars_series(datetime)
s
#> polars Series: shape: (1,)
#> Series: '' [datetime[ms]]
#> [
#>  1899-12-31 23:50:39
#> ]

as.vector(s)
#> [1] "1900-01-01 PMT"

Now the internal value is updated to match the displayed value.

# polars 0.15.0
Sys.setenv(TZ = "Europe/Paris")
datetime = as.POSIXct("1900-01-01")
datetime
#> [1] "1900-01-01 PMT"

s = polars::as_polars_series(datetime)
s
#> polars Series: shape: (1,)
#> Series: '' [datetime[ms]]
#> [
#>  1900-01-01 00:00:00
#> ]

as.vector(s)
#> [1] "1900-01-01 PMT"

This update may cause errors when converting from Polars to POSIXct for non-existent or ambiguous times. It is recommended to explicitly add a time zone before converting from Polars to R.

Sys.setenv(TZ = "America/New_York")
ambiguous_time = as.POSIXct("2020-11-01 01:00:00")
ambiguous_time
#> [1] "2020-11-01 01:00:00 EDT"

pls = polars::as_polars_series(ambiguous_time)
pls
#> polars Series: shape: (1,)
#> Series: '' [datetime[ms]]
#> [
#>  2020-11-01 01:00:00
#> ]

## This will be error!
# pls |> as.vector()

pls$dt$replace_time_zone("UTC") |> as.vector()
#> [1] "2020-11-01 01:00:00 UTC"

Removed argument eager in pl$date_range() and pl$struct() for more consistency of output. It is possible to replace eager = TRUE by calling $to_series() (#882).

New features

In the when-then-otherwise expressions, the last $otherwise() is now optional, as in Python Polars. If $otherwise() is not specified, rows that don't respect the condition set in $when() will be filled with null (#836).
<DataFrame>$head() and <DataFrame>$tail() methods now support negative row numbers (#840).
$group_by() now works with named expressions (#846).
New methods for the arr subnamespace: $median(), $var(), $std(), $shift(), $to_struct() (#867).
$min() and max() now work on categorical variables (#868).
New methods for the list subnamespace: $n_unique(), $gather_every() (#869).
Converts clock_time_point and clock_zoned_time objects from the {clock} package to Polars datetime type (#861).
New methods for the name subnamespace: $prefix_fields() and suffix_fields() (#873).
pl$Datetime()'s time_zone argument now accepts "*" to match any time zone (#887).

Bug fixes

R no longer crashes when calling an invalid Polars object that points to a null pointer (#874). This was occurring, such as when a Polars object was saved in an RDS file and loaded from another session.

Polars R Package 0.14.1

Breaking changes

Since most of the methods of Expr are now available for Series, the experimental <Series>$expr subnamespace is removed (#831). Use <Series>$<method> instead of <Series>$expr$<method>.

New features

New active bindings $flags for DataFrame to show the flags used internally for each column. The output of $flags for Series was also improved and now contains FAST_EXPLODE for Series of type list and array (#809).
Most of Expr methods are also available for Series (#819, #828, #831).
as_polars_df() for data.frame is more memory-efficient and new arguments schema and schema_overrides are added (#817).
Use polars_code_completion_activate() to enable code suggestions and autocompletion after $ on polars objects. This is an experimental feature that is disabled by default. For now, it is only supported in the native R terminal and in RStudio (#597).

Bug fixes

<Series>$list sub namespace methods returns Series class object correctly (#819).

Polars R Package 0.14.0

Breaking changes due to Rust Polars update

Rust Polars is updated to 0.37.0 (#776).
- Minimum supported Rust version (MSRV) is now 1.74.1.
- $with_row_count() for DataFrame and LazyFrame is deprecated and will be removed in 0.15.0. It is replaced by $with_row_index().
- pl$count() is deprecated and will be removed in 0.15.0. It is replaced by pl$len().
- $explode() for DataFrame and LazyFrame doesn't work anymore on string columns.
- $list$join() and pl$concat_str() gain an argument ignore_nulls. The current behavior is to return a null if the row contains any null. Setting ignore_nulls = TRUE changes that.
- All row_count_* args in reading/scanning functions are renamed row_index_*.
- $sort() for Series gains an argument nulls_last.
- $str$extract() and $str$zfill() now accept an Expr and parse strings as column names. Use pl$lit() to recover the old behavior.
- $cum_count() now starts from 1 instead of 0.

Other breaking changes

The simd feature of the Rust library is removed in favor of the new nightly feature (#800). If you specified simd via the LIBR_POLARS_FEATURES environment variable during source installations, please use nightly instead; there is no change if you specified full_features because it now contains nightly instead of simd.
The following functions were deprecated in 0.13.0 and are now removed (#783):
- $list$lengths() -> $list$len()
- pl$from_arrow() -> as_polars_df() or as_polars_series()
- pl$set_options() and pl$reset_options() -> polars_options()
$is_between() had several changes (#788):
- arguments start and end are renamed lower_bound and upper_bound. Their behaviour doesn't change.
- include_bounds is renamed closed and must be one of "left", "right", "both", or "none".
polars_info() returns a slightly changed list.
- $threadpool_size, which means the number of threads used by Polars, is changed to $thread_pool_size (#784)
- $version, which indicates the version of this package, is changed to $versions$r_package (#791).
- $rust_polars, which indicates the version of the dependent Rust Polars, is changed to $versions$rust_crate (#791).
New behavior when creating a DataFrame with a single list-variable. pl$DataFrame(x = list(1:2, 3:4)) used to create a DataFrame with two columns named "new_column" and "new_column_1", which was unexpected. It now produces a DataFrame with a single list variable. This also applies to list-column created in $with_columns() and $select() (#794).

Deprecations

pl$threadpool_size() is deprecated and will be removed in 0.15.0. Use pl$thread_pool_size() instead (#784).

New features

Implementation of the subnamespace $arr for expressions on array-type columns. An array column is similar to a list column, but is stricter as each sub-array must have the same number of elements (#790).

Other improvements

The sql feature is included in the default feature (#800). This means that functionality related to the RPolarsSQLContext class is now always included in the binary package.

Polars R Package 0.13.1

New features

New method $write_parquet() for DataFrame (#758).
S3 methods of as.data.frame() for RPolarsDataFrame and RPolarsLazyFrame accepts more arguments of as_polars_df() and <DataFrame>$to_data_frame() (#762).
S3 methods of arrow::as_arrow_table() and arrow::as_record_batch_reader() for RPolarsDataFrame no longer need the {nanoarrow} package (#754).
Some S3 methods for the {nanoarrow} package are added (#730).
- as_polars_df(<nanoarrow_array_stream>)
- as_polars_series(<nanoarrow_array>)
- as_polars_series(<nanoarrow_array_stream>)

Bug fixes

$sort() no longer panicks when descending = NULL (#748).

Other enhancements

downlit::autolink() now recognize the reference pages of this package (#739).

Polars R Package 0.13.0

Breaking changes

<Expr>$where() is removed. Use <Expr>$filter() instead (#718).
Deprecated functions from 0.12.x are removed (#714).
- <Expr>$apply() and <Expr>$map(), use $map_elements() and $map_batches() instead.
- pl$polars_info(), use polars_info() instead.
The environment variables used when building the library have been changed (#693). This only affects selecting the feature flag and selecting profiles during source installation.
- RPOLARS_PROFILE is renamed to LIBR_POLARS_PROFILE
- RPOLARS_FULL_FEATURES is removed and LIBR_POLARS_FEATURES is added. To select the full_features, set LIBR_POLARS_FEATURES="full_features".
- RPOLARS_RUST_SOURCE, which was used for development, has been removed. If you want to use library binaries located elsewhere, use LIBR_POLARS_PATH instead.
Remove the eager argument of <SQLContext>$execute(). Use the $collect() method after $execute() or as_polars_df to get the result as a DataFrame. (#719)
The argument name_generator of $list$to_struct() is renamed fields (#724).
The S3 method [ for the $list subnamespace is removed (#724).
The option polars.df_print has been renamed polars.df_knitr_print (#726).

Deprecations

$list$lengths() is deprecated and will be removed in 0.14.0. Use $list$len() instead (#724).
pl$from_arrow() is deprecated and will be removed in 0.14.0. Use as_polars_df() or as_polars_series() instead (#728).
pl$set_options() and pl$reset_options() are deprecated and will be removed in 0.14.0. See ?polars_options for details (#726).

New features

For compatibility with CRAN, the number of threads used by Polars is automatically set to 2 if the environment variable POLARS_MAX_THREADS is not set (#720). To disable this behavior and have the maximum number of threads used automatically, one of the following ways can be used:
- Build the Rust library with the disable_limit_max_threads feature.
- Set the polars.limit_max_threads option to FALSE with the options() function before loading the package.
New method $rolling() for DataFrame and LazyFrame. When this is applied, it creates an object of class RPolarsRollingGroupBy (#682, #694).
New method $group_by_dynamic() for DataFrame and LazyFrame. When this is applied, it creates an object of class RPolarsDynamicGroupBy (#691).
New method $sink_ndjson() for LazyFrame (#681).
New function pl$duration() to create a duration by components (week, day, hour, etc.), and use them with date(time) variables (#692).
New methods $list$any() and $list$all() (#709).
New function pl$from_epoch() to convert a Unix timestamp to a date(time) variable (#708).
New methods for the list subnamespace: $set_union(), $set_intersection(), $set_difference(), $set_symmetric_difference() (#712).
New option int64_conversion to specify how Int64 columns (that don't have equivalent in base R) should be converted. This option can either be set globally with pl$set_options() or on a case-by-case basis, e.g with $to_data_frame(int64_conversion =) (#706).
Several changes in $join() for DataFrame and LazyFrame (#716):
- <LazyFrame>$join() now errors if other is not a LazyFrame and <DataFrame>$join() errors if other is not a DataFrame.
- Some arguments have been reordered (e.g how now comes before left_on). This can lead to bugs if the user didn't use argument names.
- Argument how now accepts "outer_coalesce" to coalesce the join keys automatically after joining.
- New argument validate to perform some checks on join keys (e.g ensure that there is a one-to-one matching between join keys).
- New argument join_nulls to consider null values as a valid key.
<DataFrame>$describe() now works with all datatypes. It also gains an interpolation argument that is used for quantiles computation (#717).
as_polars_df() and as_polars_series() for the arrow package classes have been rewritten and work better (#727).
Options handling has been rewritten to match the standard option handling in R (#726):
- Options are now passed via options(). The option names don't change but they must be prefixed with "polars.". For example, we can now pass options(polars.strictly_immutable = FALSE).
- Options can be accessed with polars_options(), which returns a named list (this is the replacement of pl$options).
- Options can be reset with polars_options_reset() (this is the replacement of pl$reset_options()).
New function polars_envvars() to print the list of environment variables related to polars (#735).

Polars R Package 0.12.2

This is a small release including a few documentation improvements and internal updates.

Polars R Package 0.12.1

This version includes a few additional features and a large amount of documentation improvements.

Deprecations

pl$polars_info() is moved to polars_info(). pl$polars_info() is deprecated and will be removed in 0.13.0 (#662).

Rust Polars update

Rust Polars is updated to 0.36.2 (#659). Most of the changes from 0.35.x to 0.36.2 were covered in R polars 0.12.0. The main change is that pl$Utf8 is replaced by pl$String. pl$Utf8 is an alias and will keep working, but pl$String is now preferred in the documentation and in new code.

What's changed

New methods $str$reverse(), $str$contains_any(), and $str$replace_many() (#641).
New methods $rle() and $rle_id() (#648).
New functions is_polars_df(), is_polars_lf(), is_polars_series() (#658).
$gather() now accepts negative indexing (#659).

Miscellaneous

Remove the Makefile in favor of Taskfile.yml. Please use task instead of make as a task runner in the development (#654).

Polars R Package 0.12.0

BREAKING CHANGES DUE TO Rust Polars UPDATE

Rust Polars is updated to 2023-12-25 unreleased version (#601, #622). This is the same version of Python Polars package 0.20.2, so please check the upgrade guide for details too.
- pl$scan_csv() and pl$read_csv()'s comment_char argument is renamed comment_prefix.
- <DataFrame>$frame_equal() and <Series>$series_equal() are renamed to <DataFrame>$equals() and <Series>$equals().
- <Expr>$rolling_* functions gained an argument warn_if_unsorted.
- <Expr>$str$json_extract() is renamed to <Expr>$str$json_decode().
- Change default join behavior with regard to null values.
- Preserve left and right join keys in outer joins.
- count now ignores null values.
- NaN values are now considered equal.
- $gather_every() gained an argument offset.

Breaking changes and deprecations

$apply() on an Expr or a Series is renamed $map_elements(), and $map() is renamed $map_batches(). $map() and $apply() will be removed in 0.13.0 (#534).
Removed $days(), $hours(), $minutes(), $seconds(), $milliseconds(), $microseconds(), $nanoseconds(). Those were deprecated in 0.11.0 (#550).
pl$concat_list(): elements being strings are now interpreted as column names. Use pl$lit to concat with a string.
<RPolarsExpr>$lit_to_s() is renamed to <RPolarsExpr>$to_series() (#582).
<RPolarsExpr>$lit_to_df() is removed (#582).
Change class names and function names associated with class names.
- The class name of all objects created by polars (DataFrame, LazyFrame, Expr, Series, etc.) has changed. They now start with RPolars, for example RPolarsDataFrame. This will only break your code if you directly use those class names, such as in S3 methods (#554, #585).
- Private methods have been unified so that they do not have the RPolars prefix (#584).

What's changed

The Extract function ([) for DataFrame can use columns not included in the result for filtering (#547).
The Extract function ([) for LazyFrame can filter rows with Expressions (#547).
as_polars_df() for data.frame has a new argument rownames for to convert the row.names attribute to a column. This option is inspired by the tibble::as_tibble() function (#561).
as_polars_df() for data.frame has a new argument make_names_unique (#561).
New methods $str$to_date(), $str$to_time(), $str$to_datetime() as alternatives to $str$strptime() (#558).
The dim() function for DataFrame and LazyFrame correctly returns integer instead of double (#577).
The conversion of R's POSIXct class to Polars datetime now works correctly with millisecond precision (#589).
<LazyFrame>$filter(), <DataFrame>$filter(), and pl$when() now allow multiple conditions to be separated by commas, like lf$filter(pl$col("foo") == 1, pl$col("bar") != 2) (#598).
New method $replace() for expressions (#601).
Better error messages for trailing argument commas such as pl$DataFrame()$select("a",) (#607).
New function pl$threadpool_size() to get the number of threads used by Polars (#620). Thread pool size is also included in the output of pl$polars_info().

Polars R Package 0.11.0

BREAKING CHANGES DUE TO Rust Polars UPDATE

Rust Polars is updated to 0.35.0 (2023-11-17) (#515)
- changes in $write_csv() and sink_csv(): has_header is renamed include_header and there's a new argument include_bom.
- pl$cov() gains a ddof argument.
- $cumsum(), $cumprod(), $cummin(), $cummax(), $cumcount() are renamed $cum_sum(), $cum_prod(), $cum_min(), $cum_max(), $cum_count().
- take() and take_every() are renamed $gather() and gather_every().
- $shift() and $shift_and_fill() now accept Expr as input.
- when reverse = TRUE, $arg_sort() now places null values in the first positions.
- Removed argument ambiguous in $dt$truncate() and $dt$round().
- $str$concat() gains an argument ignore_nulls.

Breaking changes and deprecations

The rowwise computation when several columns are passed to pl$min(), pl$max(), and pl$sum() is deprecated and will be removed in 0.12.0. Passing several columns to these functions will now compute the min/max/sum in each column separately. Use pl$min_horizontal() pl$max_horizontal(), and pl$sum_horizontal() instead for rowwise computation (#508).
$is_not() is deprecated and will be removed in 0.12.0. Use $not() instead (#511, #531).
$is_first() is deprecated and will be removed in 0.12.0. Use $is_first_distinct() instead (#531).
In pl$concat(), the argument to_supertypes is removed. Use the suffix "_relaxed" in the how argument to cast columns to their shared supertypes (#523).
All duration methods (days(), hours(), minutes(), seconds(), milliseconds(), microseconds(), nanoseconds()) are renamed, for example from $dt$days() to $dt$total_days(). The old usage is deprecated and will be removed in 0.12.0 (#530).
DataFrame methods $as_data_frame() is removed in favor of $to_data_frame() (#533).
GroupBy methods $as_data_frame() and $to_data_frame() which were used to convert GroupBy objects to R data frames are removed. Use $ungroup() method and the as.data.frame() function instead (#533).

What's changed

Fix the installation issue on Ubuntu 20.04 (#528, thanks @brownag).
New methods $write_json() and $write_ndjson() for DataFrame (#502).
Removed argument name in pl$date_range(), which was deprecated for a while (#503).
New private method .pr$DataFrame$drop_all_in_place(df) to drop DataFrame in-place, to release memory without invoking gc(). However, if there are other strong references to any of the underlying Series or arrow arrays, that memory will specifically not be released. This method is aimed for r-polars extensions, and will be kept stable as much as possible (#504).
New functions pl$min_horizontal(), pl$max_horizontal(), pl$sum_horizontal(), pl$all_horizontal(), pl$any_horizontal() (#508).
New generic functions as_polars_df() and as_polars_lf() to create polars DataFrames and LazyFrames (#519).
New method $ungroup() for GroupBy and LazyGroupBy (#522).
New method $rolling() to apply an Expr over a rolling window based on date/datetime/numeric indices (#470).
New methods $name$to_lowercase() and $name$to_uppercase() to transform variable names (#529).
New method $is_last_distinct() (#531).
New methods of the Expressions class, $floor_div(), $mod(), $eq_missing() and $neq_missing(). The base R operators %/% and %% for Expressions are now translated to $floor_div() and $mod() (#523).
- Note that $mod() of Polars is different from the R operator %%, which is not guaranteed x == (x %% y) + y * (x %/% y). Please check the upstream issue pola-rs/polars#10570.
The extract function ([) for polars objects now behave more like for base R objects (#543).

Polars R Package 0.10.1

What's changed

The argument quote_style in $write_csv() and $sink_csv() can now take the value "never" (#483).
pl$DataFrame() now errors if the variables specified in schema do not exist in the data (#486).
S3 methods for base R functions are well documented (#494).
A bug that failing pl$SQLContext()$register() without load the package was fixed (#496).

Polars R Package 0.10.0

BREAKING CHANGES DUE TO Rust Polars UPDATE

Rust Polars is updated to 2023-10-25 unreleased version (#442)
- Minimum supported Rust version (MSRV) is now 1.73.
- New subnamespace "name" that contains methods $prefix(), $suffix() keep() (renamed from keep_name()) and map() (renamed from map_alias()).
- $dt$round() gains an argument ambiguous.
- The following methods now accept an Expr as input: $top_k(), $bottom_k(), $list$join(), $str$strip_chars(), $str$strip_chars_start(), $str$strip_chars_end(), $str$split_exact().
- The following methods were renamed:
  - $str$n_chars() -> $str$len_chars()
  - $str$lengths() -> $str$len_bytes()
  - $str$ljust() -> $str$pad_end()
  - $str$rjust() -> $str$pad_start()
- $concat() with how = "diagonal" now accepts an argument to_supertypes to automatically convert concatenated columns to the same type.
- pl$enable_string_cache() doesn't take any argument anymore. The string cache can now be disabled with pl$disable_string_cache().
- $scan_parquet() gains an argument hive_partitioning.
- $meta$tree_format() has a better formatted output.

Breaking changes

$scan_csv() and $read_csv() now match more closely the Python-Polars API (#455):
- sep is renamed separator, overwrite_dtypes is renamed dtypes, parse_dates is renamed try_parse_dates.
- new arguments rechunk, eol_char, raise_if_empty, truncate_ragged_lines
- path can now be a vector of characters indicating several paths to CSV files. This only works if all CSV files have the same schema.

What's changed

New class RPolarsSQLContext and its methods to perform SQL queries on DataFrame- like objects. To use this feature, needs to build Rust library with full features (#457).
New methods $peak_min() and $peak_max() to find local minima and maxima in an Expr (#462).
New methods $read_ndjson() and $scan_ndjson() (#471).
New method $with_context() for LazyFrame to have access to columns from other Data/LazyFrames during the computation (#475).

Polars R Package 0.9.0

BREAKING CHANGES DUE TO Rust Polars UPDATE

Rust Polars is updated to 0.33.2 (#417)
- In all date-time related methods, the argument use_earliest is replaced by ambiguous.
- In $sample() and $shuffle(), the argument fixed_seed is removed.
- In $value_counts(), the arguments multithreaded and sort (sometimes called sorted) have been swapped and renamed sort and parallel.
- $str$count_match() gains a literal argument.
- $arg_min() doesn't consider NA as the minimum anymore (this was already the behavior of $min()).
- Using $is_in() with NA on both sides now returns NA and not TRUE anymore.
- Argument pattern of $str$count_matches() can now use expressions.
- Needs Rust toolchain nightly-2023-08-26 for to build with full features.
Rename R functions to match Rust Polars
- $str$count_match() -> $str$count_matches() (#417)
- $str$strip() -> $str$strip_chars() (#417)
- $str$lstrip() -> $str$strip_chars_start() (#417)
- $str$rstrip() -> $str$strip_chars_end() (#417)
- $groupby() is renamed $group_by(). (#427)

Breaking changes

Remove some deprecated methods.
- Method $with_column() has been removed (it was deprecated since 0.8.0). Use $with_columns() instead (#402).
- Subnamespace $arr has been removed (it was deprecated since 0.8.1). Use $list instead (#402).
Setting and getting polars options is now made with pl$options, pl$set_options() and pl$reset_options() (#384).

What's changed

Bump supported R version to 4.2 or later (#435).
pl$concat() now also supports Series, Expr and LazyFrame (#407).
New method $unnest() for LazyFrame (#397).
New method $sample() for DataFrame (#399).
New method $meta$tree_format() to display an Expr as a tree (#401).
New argument schema in pl$DataFrame() and pl$LazyFrame() to override the automatic type detection (#385).
Fix bug when calling R from polars via e.g. $map() where query would not complete in one edge case (#409).
New method $cat$get_categories() to list unique values of categorical variables (#412).
New methods $fold() and $reduce() to apply an R function rowwise (#403).
New function pl$raw_list and class rpolars_raw_list a list of R Raw's, where missing is encoded as NULL to aid conversion to polars binary Series. Support back and forth conversion from polars binary literal and Series to R raw (#417).
New method $write_csv() for DataFrame (#414).
New method $sink_csv() for LazyFrame (#432).
New method $dt$time() to extract the time from a datetime variable (#428).
Method $profile() gains optimization arguments and plot-related arguments (#429).
New method pl$read_parquet() that is a shortcut for pl$scan_parquet()$collect() (#434).
Rename $str$str_explode() to $str$explode() (#436).
New method $transpose() for DataFrame (#440).
New argument eager of LazyFrame$set_optimization_toggle() (#439).
{polars} can now be installed with "R source package with Rust library binary", by a mechanism copied from the prqlr package.
```
Sys.setenv(NOT_CRAN = "true")
install.packages("polars", repos = "https://rpolars.r-universe.dev")
```
The URL and SHA256 hash of the available binaries are recorded in tools/lib-sums.tsv. (#435, #448, #450, #451)

Polars R Package 0.8.1

What's changed

New string method to_titlecase() (#371).
Although stated in news for PR (#334) strip = true was not actually set for the "release-optimized" compilation profile. Now it is, but the binary sizes seems unchanged (#377).
New vignette on best practices to improve polars performance (#188).
Subnamespace name "arr" as in <Expr>$arr$ & <Series>$arr$ is deprecated in favor of "list". The subnamespace "arr" will be removed in polars 0.9.0 (#375).

Polars R Package 0.8.0

BREAKING CHANGES DUE TO Rust Polars UPDATE

Rust Polars was updated to 0.32.0, which comes with many breaking changes and new features. Unrelated breaking changes and new features are put in separate sections (#334):

update of rust toolchain: nightly bumped to nightly-2023-07-27 and MSRV is now >=1.70.
param common_subplan_elimination = TRUE in <LazyFrame> methods $collect(), $sink_ipc() and $sink_parquet() is renamed and split into comm_subplan_elim = TRUE and comm_subexpr_elim = TRUE.
Series_is_sorted: nulls_last argument is dropped.
when-then-otherwise classes are renamed to When, Then, ChainedWhen and ChainedThen. The syntactically illegal methods have been removed, e.g. chaining $when() twice.
Github release + R-universe is compiled with profile=release-optimized, which now includes strip=false, lto=fat & codegen-units=1. This should make the binary a bit smaller and faster. See also FULL_FEATURES=true env flag to enable simd with nightly rust. For development or faster compilation, use instead profile=release.
fmt arg is renamed format in pl$Ptimes and <Expr>$str$strptime.
<Expr>$approx_unique() changed name to <Expr>$approx_n_unique().
<Expr>$str$json_extract arg pat changed to dtype and has a new argument infer_schema_length = 100.
Some arguments in pl$date_range() have changed: low -> start, high -> end, lazy = TRUE -> eager = FALSE. Args time_zone and time_unit can no longer be used to implicitly cast time types. These two args can only be used to annotate a naive time unit. Mixing time_zone and time_unit for start and end is not allowed anymore.
<Expr>$is_in() operation no longer supported for dtype null.
Various subtle changes:
- (pl$lit(NA_real_) == pl$lit(NA_real_))$lit_to_s() renders now to null not true.
- pl$lit(NA_real_)$is_in(pl$lit(NULL))$lit_to_s() renders now to false and before true
- pl$lit(numeric(0))$sum()$lit_to_s() now yields 0f64 and not null.
<Expr>$all() and <Expr>$any() have a new arg drop_nulls = TRUE.
<Expr>$sample() and <Expr>$shuffle() have a new arg fix_seed.
<DataFrame>$sort() and <LazyFrame>$sort() have a new arg maintain_order = FALSE.

OTHER BREAKING CHANGES

$rpow() is removed. It should never have been translated. Use ^ and $pow() instead (#346).
<LazyFrame>$collect_background() renamed <LazyFrame>$collect_in_background() and reworked. Likewise PolarsBackgroundHandle reworked and renamed to RThreadHandle (#311).
pl$scan_arrow_ipc is now called pl$scan_ipc (#343).

Other changes

Stream query to file with pl$sink_ipc() and pl$sink_parquet() (#343)
New method $explode() for DataFrame and LazyFrame (#314).
New method $clone() for LazyFrame (#347).
New method $fetch() for LazyFrame (#319).
New methods $optimization_toggle() and $profile() for LazyFrame (#323).
$with_column() is now deprecated (following upstream polars). It will be removed in 0.9.0. It should be replaced with $with_columns() (#313).
New lazy function translated: concat_str() to concatenate several columns into one (#349).
New stat functions pl$cov(), pl$rolling_cov() pl$corr(), pl$rolling_corr() (#351).
Add functions pl$set_global_rpool_cap(), pl$get_global_rpool_cap(), class RThreadHandle and in_background = FALSE param to <Expr>$map() and $apply(). It is now possible to run R code with <LazyFrame>collect_in_background() and/or let polars parallize R code in an R processes pool. See RThreadHandle-class in reference docs for more info. (#311)
Internal IPC/shared-mem channel to serialize and send R objects / polars DataFrame across R processes. (#311)
Compile environment flag RPOLARS_ALL_FEATURES changes name to RPOLARS_FULL_FEATURES. If 'true' will trigger something like Cargo build --features "full_features" which is not exactly the same as Cargo build --all-features. Some dev features are not included in "full_features" (#311).
Fix bug to allow using polars without library(polars) (#355).
New methods <LazyFrame>$optimization_toggle() + $profile() and enable Rust Polars feature CSE: "Activate common subplan elimination optimization" (#323)
Named expression e.g. pl$select(newname = pl$lit(2)) are no longer experimental and allowed as default (#357).
Added methods pl$enable_string_cache(), pl$with_string_cache() and pl$using_string_cache() for joining/comparing Categorical series/columns (#361).
Added an S3 generic as_polars_series() where users or developers of extensions can define a custom way to convert their format to Polars format. This generic must return a Polars series. See #368 for an example (#369).
Private API Support for Arrow Stream import/export of DataFrame between two R packages that uses Rust Polars. See R package example here (#326).

Polars R Package 0.7.0

BREAKING CHANGES

Replace the argument reverse by descending in all sorting functions. This is for consistency with the upstream Polars (#291, #293).
Bump Rust Polars from 2023-04-20 unreleased version to version 0.30.0 released in 2023-05-30 (#289).
- Rename concat_lst to concat_list.
- Rename $str$explode to $str$str_explode.
- Remove tz_aware and utc arguments from str_parse.
- in $date_range's the lazy argument is now TRUE by default.
The functions to read CSV have been renamed scan_csv and read_csv for consistency with the upstream Polars. scan_xxx and read_xxx functions are now accessed via pl, e.g. pl$scan_csv() (#305).

What's changed

New method $rename() for LazyFrame and DataFrame (#239)
<DataFrame>$unique() and <LazyFrame>$unique() gain a maintain_order argument (#238).
New pl$LazyFrame() to quickly create a LazyFrame, mostly in examples or for demonstration purposes (#240).
Polars is internally moving away from string errors to a new error-type called RPolarsErr both on rust- and R-side. Final error messages should look very similar (#233).
$columns(), $schema(), $dtypes() for LazyFrame implemented (#250).
Improvements to internal RPolarsErr. Also RPolarsErr will now print each context of the error on a separate line (#250).
Fix memory leak on error bug. Fix printing of % bug. Prepare for renaming of polars classes (#252).
Add helpful reference landing page at polars.github.io/reference_home (#223, #264).
Supports Rust 1.65 (#262, #280)
- Rust Polars' simd feature is now disabled by default. To enable it, set the environment variable RPOLARS_ALL_FEATURES to true when build r-polars (#262).
- opt-level of argminmax is now set to 1 in the release profile to support Rust < 1.66. The profile can be changed by setting the environment variable RPOLARS_PROFILE (when set to release-optimized, opt-level of argminmax is set to 3).
A new function pl$polars_info() will tell which features enabled (#271, #285, #305).
select() now accepts lists of expressions. For example, <DataFrame>$select(l_expr) works with l_expr = list(pl$col("a")) (#265).
LazyFrame gets some new S3 methods: [, dim(), dimnames(), length(), names() (#301)
<DataFrame>$glimpse() is a fast str()-like view of a DataFrame (#277).
$over() now accepts a vector of column names (#287).
New method <DataFrame>$describe() (#268).
Cross joining is now possible with how = "cross" in $join() (#310).
Add license info of all rust crates to LICENSE.note (#309).
With CRAN 0.7.0 release candidate (#308).
- New author accredited, SHIMA Tatsuya @eitsupi).
- DESCRIPTION revised.

Polars R Package 0.6.1

What's changed

use pl$set_polars_options(debug_polars = TRUE) to profile/debug method-calls of a polars query (#193)
add <DataFrame>$melt(), <DataFrame>$pivot() + <LazyFrame>$melt() methods (#232)
lazy functions translated: pl$implode, pl$explode, pl$unique, pl$approx_unique, pl$head, pl$tail (#196)
pl$list is deprecated, use pl$implode instead. (#196)
Docs improvements. (#210, #213)
Update nix flake. (#227)

Polars R Package 0.6.0

BREAKING CHANGES

Bump Rust Polars from 2023-02-17 unreleased version to 2023-04-20 unreleased version. (#183)
- top_k's reverse option is removed. Use the new bottom_k method instead.
- The name of the fmt argument of some methods (e.g. parse_date) has been changed to format.

What's changed

DataFrame objects can be subsetted using brackets like standard R data frames: pl$DataFrame(mtcars)[2:4, c("mpg", "hp")] (#140 @vincentarelbundock)
An experimental knit_print() method has been added to DataFrame that outputs HTML tables (similar to py-polars' HTML output) (#125 @eitsupi)
Series gains new methods: $mean, $median, $std, $var (#170 @vincentarelbundock)
A new option use_earliest of replace_time_zone. (#183)
A new option strict of parse_int. (#183)
Perform joins on nearest keys with method join_asof. (#172)

Polars R Package v0.5.0

BREAKING CHANGE

The package name was changed from rpolars to polars. (#84)

What's changed

Several new methods for DataFrame, LazyFrame & GroupBy translated (#103, #105 @vincentarelbundock)
Doc fixes (#102, #109 @etiennebacher)
Experimental opt-in auto completion (#96 @sorhawell)
Base R functions work on DataFrame and LazyFrame objects via S3 methods: as.data.frame, as.matrix, dim, head, length, max, mean, median, min, na.omit, names, sum, tail, unique, ncol, nrow (#107 @vincentarelbundock).

New Contributors

@etiennebacher made their first contribution in #102
@vincentarelbundock made their first contribution in #103

Release date: 2023-04-16. Full changelog: v0.4.6...v0.5.0