[Python] Enumerate each row for each id [duplicate]

This is my dataframe:

id url
25 google.com/main
25 google.com/buy
25 google.com/videos
144 google.com/buy
144 google.com/videos
144 google.com/pictures
144 google.com/maps
992 google.com/main
992 google.com/buy


I need to create a new column "row_number" and enumearate each id. I want this:

id url row_number
25 google.com/main 1
25 google.com/buy 2
25 google.com/videos 3
144 google.com/buy 1
144 google.com/videos 2
144 google.com/pictures 3
144 google.com/maps 4
992 google.com/main 1
992 google.com/buy 2


i was trying:

df['row_number'] = df.groupby('id').apply(lambda x: list(range(1, len(x)+1))).explode()


but it writes an error:

ValueError: cannot reindex on an axis with duplicate labels

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