polars.enable_string_cache#

polars.enable_string_cache(enable: bool) → None[source]#

Enable (or disable) the global string cache.

This ensures that casts to Categorical dtypes will have the same category values when string values are equal.

Parameters:

enable: Enable or disable the global string cache.

Examples

>>> pl.enable_string_cache(True)
>>> df1 = pl.DataFrame(
...     data={"color": ["red", "green", "blue", "orange"], "value": [1, 2, 3, 4]},
...     schema={"color": pl.Categorical, "value": pl.UInt8},
... )
>>> df2 = pl.DataFrame(
...     data={
...         "color": ["yellow", "green", "orange", "black", "red"],
...         "char": ["a", "b", "c", "d", "e"],
...     },
...     schema={"color": pl.Categorical, "char": pl.Utf8},
... )
>>> df_join = df1.join(df2, how="inner", on="color")
>>> df_join
shape: (3, 3)
┌────────┬───────┬──────┐
│ color  ┆ value ┆ char │
│ ---    ┆ ---   ┆ ---  │
│ cat    ┆ u8    ┆ str  │
╞════════╪═══════╪══════╡
│ green  ┆ 2     ┆ b    │
│ orange ┆ 4     ┆ c    │
│ red    ┆ 1     ┆ e    │
└────────┴───────┴──────┘