Slice/split string Series at various positions

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借酒劲吻你
借酒劲吻你 2021-01-18 21:48

I\'m looking to split a string Series at different points depending on the length of certain substrings:

In [47]: df = pd.DataFrame([\'group9class1\', \'grou         


        
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  •  轻奢々
    轻奢々 (楼主)
    2021-01-18 22:33

    This works, by using double [[]] you can access the index value of the current element so you can index into the split_locations series:

    In [119]:    
    df[['group_class']].apply(lambda x: pd.Series([x.str[split_locations[x.name]:][0], x.str[:split_locations[x.name]][0]]), axis=1)
    Out[119]:
             0        1
    0   class1   group9
    1   class2  group10
    2  class20  group11
    

    Or as @ajcr has suggested you can extract:

    In [106]:
    
    df['group_class'].str.extract(r'(?Pgroup[0-9]+)(?Pclass[0-9]+)')
    Out[106]:
         group    class
    0   group9   class1
    1  group10   class2
    2  group11  class20
    

    EDIT

    Regex explanation:

    the regex came from @ajcr (thanks!), this uses str.extract to extract groups, the groups become new columns.

    So ?P here identifies an id for a specific group to look for, if this is missing then an int will be returned for the column name.

    so the rest should be self-explanatory: group[0-9] looks for the string group followed by the digits in range [0-9] which is what the [] indicate, this is equivalent to group\d where \d means digit.

    So it could be re-written as:

    df['group_class'].str.extract(r'(?Pgroup\d+)(?Pclass\d+)')
    

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