polars.DataFrame.rename#
- DataFrame.rename( ) DataFrame [source]#
Rename column names.
- Parameters:
- mapping
Key value pairs that map from old name to new name, or a function that takes the old name as input and returns the new name.
- strict
Validate that all column names exist in the current schema, and throw an exception if any do not. (Note that this parameter is a no-op when passing a function to
mapping
).
Examples
>>> df = pl.DataFrame( ... {"foo": [1, 2, 3], "bar": [6, 7, 8], "ham": ["a", "b", "c"]} ... ) >>> df.rename({"foo": "apple"}) shape: (3, 3) ┌───────┬─────┬─────┐ │ apple ┆ bar ┆ ham │ │ --- ┆ --- ┆ --- │ │ i64 ┆ i64 ┆ str │ ╞═══════╪═════╪═════╡ │ 1 ┆ 6 ┆ a │ │ 2 ┆ 7 ┆ b │ │ 3 ┆ 8 ┆ c │ └───────┴─────┴─────┘ >>> df.rename(lambda column_name: "c" + column_name[1:]) shape: (3, 3) ┌─────┬─────┬─────┐ │ coo ┆ car ┆ cam │ │ --- ┆ --- ┆ --- │ │ i64 ┆ i64 ┆ str │ ╞═════╪═════╪═════╡ │ 1 ┆ 6 ┆ a │ │ 2 ┆ 7 ┆ b │ │ 3 ┆ 8 ┆ c │ └─────┴─────┴─────┘