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pythonpandasregex

Regex to remove character before a character set

I have dataframe with column 'code'.

import pandas as pd
df = pd.DataFrame({'code': ['10SGD35/AA501/10SGD35/AA599/10SGD36/AA501/10SGD36AA599/10SGD37/AA501/10SGD37/AA527',
                            '10SGD08/AA701/10SGD08/AA704/10SGD09/AA701/10SGD09AA708']})

How can I drop character '/' before character set 'AA' in pandas?

                                                                            code
0  10SGD35AA501/10SGD35AA599/10SGD36AA501/10SGD36AA599/10SGD37AA501/10SGD37AA527
1                            10SGD08AA701/10SGD08AA704/10SGD09AA701/10SGD09AA708

I use str.replace:

df['data'] = df['data'].str.replace('|(?=AA)', '', regex=True)

This regex does not work. Where is the mistake?

Solution

  • Use a regex with a lookahead and str.replace:

    df['code'] = df['code'].str.replace('/(?=AA)', '', regex=True)

    Output:

                                                                                code   text
0  10SGD35AA501/10SGD35AA599/10SGD36AA501/10SGD36AA599/10SGD37AA501/10SGD37AA527  text1
1                            10SGD08AA701/10SGD08AA704/10SGD09AA701/10SGD09AA708  text2
    regex

    regex demo

    /       # match "/"
(?=AA)  # only if followed by "AA"