Create a new column only with the year from a string variable-CodePudding

I need to create a new column in the dataset that contains only the year. The dpro columns contains more text example: 1913/12/30 : classé MH. I´ve tried with other arguments but Something is missing and I am junior in python. Thanks

Code:

monuments["year_protec"] = pd.to_datetime(monuments["dpro"], format ="%Y",errors ="coerce")
monuments.head()

CodePudding user response：

Maybe you can try to clean up the string first, and convert it into datetime format and finally get the year part.

import pandas as pd
import re

s = ["1913/12/30 : classé MH", "1913/12/30 : classé MH","1913/12/30 : classé MH"]
df = pd.DataFrame({"date" : s})

#df 

    date
0   1913/12/30 : classé MH
1   1913/12/30 : classé MH
2   1913/12/30 : classé MH

drop = re.compile(r'[^(\d{4}\/\d{2}\/\d{2})]')
df["clean_date"] = df["date"].str.replace(drop, "")
df["year"] = pd.to_datetime(df["clean_date"], format = "%Y/%m/%d").dt.year
# df
    date                    clean_date  year
0   1913/12/30 : classé MH  1913/12/30  1913
1   1913/12/30 : classé MH  1913/12/30  1913
2   1913/12/30 : classé MH  1913/12/30  1913