Find the indexes of all regex matches?

This is what you want: (source)

re.finditer(pattern, string[, flags]) 

Return an iterator yielding MatchObject instances over all non-overlapping matches for the RE pattern in string. The string is scanned left-to-right, and matches are returned in the order found. Empty matches are included in the result unless they touch the beginning of another match.

You can then get the start and end positions from the MatchObjects.

e.g.

[(m.start(0), m.end(0)) for m in re.finditer(pattern, string)]

#To get indice of all occurence

S = input() # Source String 
k = input() # String to be searched
import re
pattern = re.compile(k)
r = pattern.search(S)
if not r: print("(-1, -1)")
while r:
    print("({0}, {1})".format(r.start(), r.end() - 1))
    r = pattern.search(S,r.start() + 1)

This should solve your issue pattern=r"(?=(\"[^\"]+\"|'[^']+'))"

Then use the following to get all overlapping indices,

indicesTuple=[(mObj.start(1),mObj.end(1)-1) for mObj in re.finditer(pattern,input)]