how to split attached words and slang look up in a text file in python?

I have a text file which has multiple attached words like RainyDay, PlayingInTheCold etc. These words can be split into normal forms using regex to make them into meaningful words.

import re, string, html
with open("1.txt", "r") as fin, open("2.txt", "w") as fout:
    for text in fin:
        words = text.split()
        cleaned = " ".join(re.findall('[A-Z][^A-Z]*', words))
        fout.write(cleaned)

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error: Also, there are many slang words like helo, luv which should be converted to hello, love. I am trying like this

with open("1.txt", "r") as fin, open("2.txt", "w") as fout:
    for text in fin:
        words = text.split()
        words = slang_loopup(words)
        text = ' '.join(words)
        fout.write(cleaned)

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I tried _slang_loopup() also but same NameError
error is:
Can someone please help me?
Thanks