How to replace dash between characters with space using regex

Question

I want to replace dashes which appear between letters with a space using regex. For example to replace ab-cd with ab cd

The following matc

Answer 1

You need to capture the characters before and after the - to a group and use them for replacement, i.e.:

import re
subject = "ab-cd"
subject = re.sub(r"([a-z])\-([a-z])", r"\1 \2", subject , 0, re.IGNORECASE)
print subject
#ab cd

---

DEMO

http://ideone.com/LAYQWT

---

REGEX EXPLANATION

([A-z])\-([A-z])

Match the regex below and capture its match into backreference number 1 «([A-z])»
   Match a single character in the range between “A” and “z” «[A-z]»
Match the character “-” literally «\-»
Match the regex below and capture its match into backreference number 2 «([A-z])»
   Match a single character in the range between “A” and “z” «[A-z]»

\1 \2

Insert the text that was last matched by capturing group number 1 «\1»
Insert the character “ ” literally « »
Insert the text that was last matched by capturing group number 2 «\2»