polars.Expr.dt.is_leap_year

Expr.dt.is_leap_year() → Expr

Determine whether the year of the underlying date is a leap year.

Applies to Date and Datetime columns.

Returns:

Expr

Expression of data type Boolean.

Examples

>>> from datetime import datetime
>>> start = datetime(2000, 1, 1)
>>> stop = datetime(2002, 1, 1)
>>> df = pl.DataFrame(
...     {"date": pl.date_range(start, stop, interval="1y", eager=True)}
... )
>>> df
shape: (3, 1)
┌─────────────────────┐
│ date                │
│ ---                 │
│ datetime[μs]        │
╞═════════════════════╡
│ 2000-01-01 00:00:00 │
│ 2001-01-01 00:00:00 │
│ 2002-01-01 00:00:00 │
└─────────────────────┘
>>> df.select(pl.col("date").dt.is_leap_year())
shape: (3, 1)
┌───────┐
│ date  │
│ ---   │
│ bool  │
╞═══════╡
│ true  │
│ false │
│ false │
└───────┘