movies['year'] = movies['title'].str.extract('.*\((.*)\).*', expand=True)
In the above line of code please explain the use of every character in the .*\((.*)\).*. How it will extract 1995 from Toy Story(1995)?
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PRASANTH BATTULA
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That's a regular expression: https://stackoverflow.com/questions/4736/learning-regular-expressions – Willem Van Onsem Oct 12 '19 at 13:11
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You can use regex101 here: https://regex101.com/ – Willem Van Onsem Oct 12 '19 at 13:11
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What you doing above only works as your year is in (), for example the below doesn't work:
In [98]: pd.Series(["Toy Story 1995"]).str.extract('.*\((.*)\).*', expand=True)
Out[98]:
0
0 NaN
In [99]: pd.Series(["Toy Story (test)"]).str.extract('.*\((.*)\).*', expand=True)
Out[99]:
0
0 test
The above is finding all elements between brackets. The *. is literally matching all elements, the / is escaping the outer () and the inner () are for specifying the capturing group i.e. what pattern.
You probably want to do something as per below, /d is short hand for digit [0-9] and {4} highlights the expected length, so if you know the year format is yyyy then could do the below:
movies['title'].str.extract('(\d{4})')
This thread has a more general example using /d+
RK1
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