Series.str.extractall()

For each subject string in the Series, extract groups from all matches of regular expression pat. When each subject string in the Series has exactly one match, extractall(pat).xs(0, level=?match?) is the same as extract(pat).

Examples

A pattern with one group will return a DataFrame with one column. Indices with no matches will not appear in the result.

>>> s = Series(["a1a2", "b1", "c1"], index=["A", "B", "C"])
>>> s.str.extractall("[ab](\d)")
         0
  match
A 0      1
  1      2
B 0      1

Capture group names are used for column names of the result.

>>> s.str.extractall("[ab](?P<digit>\d)")
        digit
  match
A 0         1
  1         2
B 0         1

A pattern with two groups will return a DataFrame with two columns.

>>> s.str.extractall("(?P<letter>[ab])(?P<digit>\d)")
        letter digit
  match
A 0          a     1
  1          a     2
B 0          b     1

Optional groups that do not match are NaN in the result.

>>> s.str.extractall("(?P<letter>[ab])?(?P<digit>\d)")
        letter digit
  match
A 0          a     1
  1          a     2
B 0          b     1
C 0        NaN     1