Regex in Python to put spaces between words starting with capital letters

Given an array of characters, which is basically a sentence. However, there is no space between different words and the first letter of every word is in uppercase. You need to print this sentence after following amendments:
(i) Put a single space between these words.
(ii) Convert the uppercase letters to lowercase.


Input : BruceWayneIsBatman
Output : bruce wayne is batman

Input :  GeeksForGeeks
Output :  geeks for geeks

We have existing solution for this problem, please refer Put spaces between words starting with capital letters link.

We can solve this problem quickly in python using findall() method of re (regex) library.
Approach :

  1. Split each word starting with capital letter using re.findall(expression, str) method.
  2. Now change capital letter of each word to lowercase and concatenate each word with space.




# Put spaces between words starting with
# capital letters using Regex in Python
import re
def putSpace(input):
    # regex [A-Z][a-z]* means any string starting 
    # with capital character followed by many 
    # lowercase letters 
    words = re.findall('[A-Z][a-z]*', input)
    # Change first letter of each word into lower
    # case
    result = []
    for word in words:
        word = chr( ord (word[0]) + 32) + word[1:]
    print ' '.join(result)
# Driver program
if __name__ == "__main__":
    input = 'BruceWayneIsBatman'



bruce wayne is batman

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