Extract day from underlying Date representation. Can be performed on Date and Datetime.
Returns the day of month starting from 1. The return value ranges from 1 to 31. (The last day of month differs by months.)
day as pl.UInt32
Extract hour from underlying DateTime representation. Can be performed on Datetime.
Returns the hour number from 0 to 23.
Hour as UInt32
Extract minutes from underlying DateTime representation. Can be performed on Datetime.
Returns the minute number from 0 to 59.
minute as UInt32
Extract month from underlying Date representation. Can be performed on Date and Datetime.
Returns the month number starting from 1. The return value ranges from 1 to 12.
Month as UInt32
Extract seconds from underlying DateTime representation. Can be performed on Datetime.
Returns the number of nanoseconds since the whole non-leap second. The range from 1,000,000,000 to 1,999,999,999 represents the leap second.
Nanosecond as UInt32
Extract ordinal day from underlying Date representation. Can be performed on Date and Datetime.
Returns the day of year starting from 1. The return value ranges from 1 to 366. (The last day of year differs by years.)
Day as UInt32
Divide the date/datetime range into buckets.
Ambiguous results are localised using the DST offset of the original timestamp -
for example, rounding '2022-11-06 01:20:00 CST' by '1h' results in
'2022-11-06 01:00:00 CST', whereas rounding '2022-11-06 01:20:00 CDT' by
'1h' results in '2022-11-06 01:00:00 CDT'.
Expr Expression of data type :class:Date or :class:Datetime.
The every argument is created with the following small string formatting language:
By "calendar day", we mean the corresponding time on the next day (which may not be 24 hours, due to daylight savings). Similarly for "calendar week", "calendar month", "calendar quarter", and "calendar year".
--------
const df = pl.DataFrame([
pl.Series("datetime", [
new Date(Date.parse("2020-01-01T01:30:00.002+00:00")),
new Date(Date.parse("2020-01-01T02:02:01.030+00:00")),
new Date(Date.parse("2020-01-01T04:42:20.001+00:00")),
])]);
>>> df.select("datetime", pl.col("datetime").dt.round("1h").alias("hr0"));
shape: (3, 2)
┌─────────────────────────┬─────────────────────┐
│ datetime ┆ hr0 │
│ --- ┆ --- │
│ datetime[ms] ┆ datetime[ms] │
╞═════════════════════════╪═════════════════════╡
│ 2020-01-01 01:30:00.002 ┆ 2020-01-01 02:00:00 │
│ 2020-01-01 02:02:01.030 ┆ 2020-01-01 02:00:00 │
│ 2020-01-01 04:42:20.001 ┆ 2020-01-01 05:00:00 │
└─────────────────────────┴─────────────────────┘
>>> df.select("datetime", pl.col("datetime").dt.round("30m").alias("hr30m"));
shape: (3, 2)
┌─────────────────────────┬─────────────────────┐
│ datetime ┆ hr30m │
│ --- ┆ --- │
│ datetime[ms] ┆ datetime[ms] │
╞═════════════════════════╪═════════════════════╡
│ 2020-01-01 01:32:00.002 ┆ 2020-01-01 01:30:00 │
│ 2020-01-01 02:02:01.030 ┆ 2020-01-01 02:00:00 │
│ 2020-01-01 04:42:20.001 ┆ 2020-01-01 05:00:00 │
└─────────────────────────┴─────────────────────┘
Extract seconds from underlying DateTime representation. Can be performed on Datetime.
Returns the second number from 0 to 59.
Second as UInt32
Format Date/datetime with a formatting rule: See chrono strftime/strptime.
Return timestamp in ms as Int64 type.
Divide the date/datetime range into buckets. Each date/datetime is mapped to the start of its bucket using the corresponding local datetime. Note that:
'2022-11-06 01:30:00 CST' by
'1h' results in '2022-11-06 01:00:00 CST', whereas truncating
'2022-11-06 01:30:00 CDT' by '1h' results in
'2022-11-06 01:00:00 CDT'.The size of each bucket.
The every argument is created with
the following string language:
By "calendar day", we mean the corresponding time on the next day (which may not be 24 hours, due to daylight savings). Similarly for "calendar week", "calendar month", "calendar quarter", and "calendar year".
Expr Expression of data type :class:Date or :class:Datetime.
--------
const df = pl.DataFrame([
pl.Series("datetime", [
new Date(Date.parse("2020-01-01T01:32:00.002+00:00")),
new Date(Date.parse("2020-01-01T02:02:01.030+00:00")),
new Date(Date.parse("2020-01-01T04:42:20.001+00:00")),
])]);
>>> df.select("datetime", pl.col("datetime").dt.truncate("1h").alias("hr0"));
shape: (3, 2)
┌─────────────────────────┬─────────────────────┐
│ datetime ┆ hr0 │
│ --- ┆ --- │
│ datetime[ms] ┆ datetime[ms] │
╞═════════════════════════╪═════════════════════╡
│ 2020-01-01 01:32:00.002 ┆ 2020-01-01 01:00:00 │
│ 2020-01-01 02:02:01.030 ┆ 2020-01-01 02:00:00 │
│ 2020-01-01 04:42:20.001 ┆ 2020-01-01 04:00:00 │
└─────────────────────────┴─────────────────────┘
>>> df.select("datetime", pl.col("datetime").dt.truncate("30m").alias("hr30m"));
shape: (3, 2)
┌─────────────────────────┬─────────────────────┐
│ datetime ┆ hr30m │
│ --- ┆ --- │
│ datetime[ms] ┆ datetime[ms] │
╞═════════════════════════╪═════════════════════╡
│ 2020-01-01 01:32:00.002 ┆ 2020-01-01 01:30:00 │
│ 2020-01-01 02:02:01.030 ┆ 2020-01-01 02:00:00 │
│ 2020-01-01 04:42:20.001 ┆ 2020-01-01 04:30:00 │
└─────────────────────────┴─────────────────────┘
Extract the week from the underlying Date representation. Can be performed on Date and Datetime
Returns the ISO week number starting from 1. The return value ranges from 1 to 53. (The last week of year differs by years.)
Week number as UInt32
Extract the week day from the underlying Date representation. Can be performed on Date and Datetime.
Returns the weekday number where monday = 0 and sunday = 6
Week day as UInt32
Extract year from underlying Date representation. Can be performed on Date and Datetime.
Returns the year number in the calendar date.
Year as Int32
Functions that can be applied to a Date or Datetime column.