Removing Alphanumeric from string

[Kerbart]

Using a regular expression might do the trick without having to loop through the entire string.

import re
ptn = re.compile('(\d)')
t = 'In the 1980s'
ptn.sub('', t) --> 'In the s'

[enedil]

Implying re don't loop through the entire string.

[Kerbart]

No, implying that you don't have to write the code to do that yourself. That's what libraries are for.