class_docstr: Series.str namespace.
class_docstr_tok: ["Series.str","namespace","."]
docstr: Pad the start of the string with zeros until it reaches the given length.
  
  A sign prefix (`-`) is handled by inserting the padding after the sign
  character rather than before.
  
  Parameters
  ----------
  length
      Pad the string until it reaches this length. Strings with length equal to
      or greater than this value are returned as-is.
  
  See Also
  --------
  pad_start
  
  Notes
  -----
  This method is intended for padding numeric strings. If your data contains
  non-ASCII characters, use :func:`pad_start` instead.
  
  Examples
  --------
  >>> s = pl.Series([-1, 123, 999999, None])
  >>> s.cast(pl.String).str.zfill(4)
  shape: (4,)
  Series: '' [str]
  [
          "-001"
          "0123"
          "999999"
          null
  ]
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code: def zfill(self, length: int) -> Series:
      """
      Pad the start of the string with zeros until it reaches the given length.
  
      A sign prefix (`-`) is handled by inserting the padding after the sign
      character rather than before.
  
      Parameters
      ----------
      length
          Pad the string until it reaches this length. Strings with length equal to
          or greater than this value are returned as-is.
  
      See Also
      --------
      pad_start
  
      Notes
      -----
      This method is intended for padding numeric strings. If your data contains
      non-ASCII characters, use :func:`pad_start` instead.
  
      Examples
      --------
      >>> s = pl.Series([-1, 123, 999999, None])
      >>> s.cast(pl.String).str.zfill(4)
      shape: (4,)
      Series: '' [str]
      [
              "-001"
              "0123"
              "999999"
              null
      ]
  
      """
  
imports: from __future__ import annotations
  from typing import TYPE_CHECKING
  from polars.series.utils import expr_dispatch
  from polars.utils.deprecation import deprecate_renamed_function, deprecate_renamed_parameter
label_desc: Use image node_id 33 for calling the StringNameSpace obj's underlying member method code with example usage: obj.zfill(length) without return types