pandas.Series.str.split¶
-
Series.str.
split
(pat=None, n=-1, expand=False)[source]¶ Split strings around given separator/delimiter.
Splits the string in the Series/Index from the beginning, at the specified delimiter string. Equivalent to
str.split()
.Parameters: - pat : str, optional
String or regular expression to split on. If not specified, split on whitespace.
- n : int, default -1 (all)
Limit number of splits in output.
None
, 0 and -1 will be interpreted as return all splits.- expand : bool, default False
Expand the splitted strings into separate columns.
- If
True
, return DataFrame/MultiIndex expanding dimensionality. - If
False
, return Series/Index, containing lists of strings.
- If
Returns: - Series, Index, DataFrame or MultiIndex
Type matches caller unless
expand=True
(see Notes).
See also
Series.str.split
- Split strings around given separator/delimiter.
Series.str.rsplit
- Splits string around given separator/delimiter, starting from the right.
Series.str.join
- Join lists contained as elements in the Series/Index with passed delimiter.
str.split
- Standard library version for split.
str.rsplit
- Standard library version for rsplit.
Notes
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.Examples
>>> s = pd.Series(["this is a regular sentence", "https://docs.python.org/3/tutorial/index.html", np.nan])
In the default setting, the string is split by whitespace.
>>> s.str.split() 0 [this, is, a, regular, sentence] 1 [https://docs.python.org/3/tutorial/index.html] 2 NaN dtype: object
Without the n parameter, the outputs of rsplit and split are identical.
>>> s.str.rsplit() 0 [this, is, a, regular, sentence] 1 [https://docs.python.org/3/tutorial/index.html] 2 NaN dtype: object
The n parameter can be used to limit the number of splits on the delimiter. The outputs of split and rsplit are different.
>>> s.str.split(n=2) 0 [this, is, a regular sentence] 1 [https://docs.python.org/3/tutorial/index.html] 2 NaN dtype: object
>>> s.str.rsplit(n=2) 0 [this is a, regular, sentence] 1 [https://docs.python.org/3/tutorial/index.html] 2 NaN dtype: object
The pat parameter can be used to split by other characters.
>>> s.str.split(pat = "/") 0 [this is a regular sentence] 1 [https:, , docs.python.org, 3, tutorial, index... 2 NaN dtype: object
When using
expand=True
, the split elements will expand out into separate columns. If NaN is present, it is propagated throughout the columns during the split.>>> s.str.split(expand=True) 0 1 2 3 0 this is a regular 1 https://docs.python.org/3/tutorial/index.html None None None 2 NaN NaN NaN NaN 4 0 sentence 1 None 2 NaN
For slightly more complex use cases like splitting the html document name from a url, a combination of parameter settings can be used.
>>> s.str.rsplit("/", n=1, expand=True) 0 1 0 this is a regular sentence None 1 https://docs.python.org/3/tutorial index.html 2 NaN NaN