Regex to remove periods in acronyms?

Question

I want to remove periods in acronyms from a string of text, but I also want o leave regular periods (at the end of a sentence for example) in tact.

So the following sentence:

"The C.I.A. is a department in the U.S. Government."

Should become

"The CIA is a department in the US Government."

Is there a clean way to do this using Python? So far I have a two step process:

words = "The C.I.A. is a department in the U.S. Government."
words = re.sub(r'([A-Z].[A-Z.]*)\.', r'\1', words)
print words
# The C.I.A is a department in the U.S Government.    
words = re.sub(r'\.([A-Z])', r'\1', words)
print words
# The CIA is a department in the US Government.

Answer 1

Probably this?

>>> re.sub(r'(?<!\w)([A-Z])\.', r'\1', s)
'The CIA is a department in the US Government.'

Replace single dots that are preceded by an uppercase single letter provided the single letter is not immediately preceded by anything in the \w character set. The later criterion is enforced by the negative lookbehind assertion - (?<!\w).