polars.Expr.str.strip_chars_start#

Expr.str.strip_chars_start(characters: IntoExprColumn | None = None) → Expr[source]#

Remove leading characters.

Note

This method strips any characters present in characters from the start of the input, no matter their order. To strip a prefix (i.e. a “word” of characters in a certain order), use strip_prefix() instead.

Parameters:

characters: The set of characters to be removed. All combinations of this set of characters will be stripped. If set to None (default), all whitespace is removed instead.

See also

strip_prefix
strip_chars_end

Examples

>>> df = pl.DataFrame({"foo": [" hello ", "\tworld"]})
>>> df.with_columns(foo_strip_start=pl.col("foo").str.strip_chars_start())
shape: (2, 2)
┌─────────┬─────────────────┐
│ foo     ┆ foo_strip_start │
│ ---     ┆ ---             │
│ str     ┆ str             │
╞═════════╪═════════════════╡
│  hello  ┆ hello           │
│   world   ┆ world           │
└─────────┴─────────────────┘

Characters can be stripped by passing a string as argument. Note that whitespace will not be stripped automatically when doing so.

>>> df.with_columns(
...     foo_strip_start=pl.col("foo").str.strip_chars_start("wod\t"),
... )
shape: (2, 2)
┌─────────┬─────────────────┐
│ foo     ┆ foo_strip_start │
│ ---     ┆ ---             │
│ str     ┆ str             │
╞═════════╪═════════════════╡
│  hello  ┆  hello          │
│   world   ┆ rld             │
└─────────┴─────────────────┘

The order of the provided characters does not matter, they behave like a set.

>>> pl.DataFrame({"foo": ["aabcdef"]}).with_columns(
...     foo_strip_start=pl.col("foo").str.strip_chars_start("cba")
... )
shape: (1, 2)
┌─────────┬─────────────────┐
│ foo     ┆ foo_strip_start │
│ ---     ┆ ---             │
│ str     ┆ str             │
╞═════════╪═════════════════╡
│ aabcdef ┆ def             │
└─────────┴─────────────────┘