StringMethods.split(pat: str = None, n: int = - 1, expand: bool = False, regex: bool = None) SeriesOrIndex#

Split strings around given separator/delimiter.

Splits the string in the Series/Index from the beginning, at the specified delimiter string. Similar to str.split().

patstr, default None

String or regular expression to split on. If not specified, split on whitespace.

nint, default -1 (all)

Limit number of splits in output. None, 0, and -1 will all be interpreted as “all splits”.

expandbool, default False

Expand the split strings into separate columns.

  • If True, return DataFrame/MultiIndex expanding dimensionality.

  • If False, return Series/Index, containing lists of strings.

regexbool, default None

Determines if the passed-in pattern is a regular expression:

  • If True, assumes the passed-in pattern is a regular expression

  • If False, treats the pattern as a literal string.

  • If pat length is 1, treats pat as a literal string.

Series, Index, DataFrame or MultiIndex

Type matches caller unless expand=True (see Notes).

See also


Splits string around given separator/delimiter, starting from the right.


Standard library version for split.


Standard library version for rsplit.


The handling of the n keyword depends on the number of found splits:

  • If found splits > n, make first n splits only

  • If found splits <= n, make all splits

  • If for a certain row the number of found splits < n, append None for padding up to n if expand=True.

If using expand=True, Series and Index callers return DataFrame and MultiIndex objects, respectively.


>>> import cudf
>>> data = ["this is a regular sentence",
...     "", None]
>>> s = cudf.Series(data)
>>> s
0            this is a regular sentence
2                                  <NA>
dtype: object

In the default setting, the string is split by whitespace.

>>> s.str.split()
0        [this, is, a, regular, sentence]
1    []
2                                    None
dtype: list

Without the n parameter, the outputs of rsplit and split are identical.

>>> s.str.rsplit()
0        [this, is, a, regular, sentence]
1    []
2                                    None
dtype: list

The n parameter can be used to limit the number of splits on the delimiter.

>>> s.str.split(n=2)
0          [this, is, a regular sentence]
1    []
2                                    None
dtype: list

The pat parameter can be used to split by other characters.

>>> s.str.split(pat="/")
0               [this is a regular sentence]
1    [https:, ,, index.html]
2                                       None
dtype: list

When using expand=True, the split elements will expand out into separate columns. If <NA> value is present, it is propagated throughout the columns during the split.

>>> s.str.split(expand=True)
                                    0     1     2        3         4
0                                this    is     a  regular  sentence
1  <NA>  <NA>     <NA>      <NA>
2                                <NA>  <NA>  <NA>     <NA>      <NA>