regex - removing words with numbers and letters from command line input in python 3: error -

i'm having trouble getting regex remove words contain digits , letters. keep getting "typeerror: expected string or buffer" can provide appreciated.

$ testing abc sorted_word = re.sub("\s+\d\s+", "", word_sort).strip()   file "/usr/lib64/python2.6/re.py", line 151, in sub     return _compile(pattern, 0).sub(repl, string, count) typeerror: expected string or buffer  #! /usr/bin/env python import os import sys import re   in_list = sys.argv  def word_sort(in_list):     word_sort = " 1a "     word_sort = sorted(in_list[1:], key=len)     in word_sort:         punctuation = '.',',',';','!',' / ','"','?' #strips punctuation words         if in punctuation: #removes punctuation             word_sort = word_sort.replace(i," ")     word_sort= sorted(word_sort, key=lambda l: (l.lower(), l))     sorted_word = " 1a "     sorted_word = re.sub("\s+\d\s+", "", word_sort).strip()     return sorted_word  print (word_sort(in_list)) 

this:

word_sort= sorted(word_sort, key=lambda l: (l.lower(), l))

iterates through word_sort string doesn't create str object, list of sorted characters, re module chokes on it.

you have join characters again recompose string:

word_sort= "".join(sorted(word_sort, key=lambda l: (l.lower(), l))) 

small tester:

>>> sorted("dcba") ['a', 'b', 'c', 'd'] >>> "".join(sorted("dcba")) 'abcd' 

btw: should avoid call function , local variables same name word_sort. it's difficult read. , fortunately don't call function recursively :)