So far I've come up with the method below but my question is is there a shorter method out there that has the same result?

My Code :

input_str       = "myStrIngFullOfStUfFiWannAReplaCE_StUfFs"
replace_str     = "stuff"
replacer_str    = "banana"print input_str
# prints: myStrIngFullOfStUfFiWannAReplaCE_StUfFsif replace_str.lower() in input_str.lower():            # Check if even in the stringbegin_index = input_str.lower().find( replace_str )end_index   = begin_index + len( replace_str )replace_section = input_str[ begin_index : end_index ]case_list = []for char in replace_section:                        # Get cases of characters in the section to be replacedcase_list.append( char.istitle() )while len( replacer_str ) > len(case_list):case_list += case_listsameCase_replacer_str   = ""                        # Set match the replacer string's case to the replacereplacer_str            = replacer_str.lower()for index in range( len(replacer_str) ):char = replacer_str[ index ]case = case_list[ index ]if case == True:char = char.title()sameCase_replacer_str += charinput_str = input_str.replace( replace_section , sameCase_replacer_str )print input_str
# prints: myStrIngFullOfBaNaNAiWannAReplaCE_BaNaNAs

I'd use something like this:

import redef replacement_func(match, repl_pattern):match_str = match.group(0)repl = ''.join([r_char if m_char.islower() else r_char.upper()for r_char, m_char in zip(repl_pattern, match_str)])repl += repl_pattern[len(match_str):]return replinput_str = "myStrIngFullOfStUfFiWannAReplaCE_StUfFs"
print re.sub('stuff',lambda m: replacement_func(m, 'banana'),input_str, flags=re.I)

Example output:

myStrIngFullOfBaNaNaiWannAReplaCE_BaNaNas

Notes:

• This handles the case in which the different matches have different upper/lower case combinations.
• It's assumed that the replacement pattern is in lower case (that's very easy to change, anyway).
• If the replacement pattern is longer than the match, the same case as in the pattern is used.