flask - how do I modify a url that I pick at random in python -

i have app show images reddit. images come http://imgur.com/cuv9oau, when need make them http://i.imgur.com/cuv9oau.jpg. add (i) @ beginning , (.jpg) @ end.

this function should need. expanded on @jh314's response , made code little less compact , checked url started http://imgur.com code cause issues other urls, google search included. replaces first instance, causes issues.

def fiximgurlinks(url):     if url.lower().startswith("http://imgur.com"):         url = url.replace("http://imgur", "http://i.imgur",1) # replace first instance.         if not url.endswith(".jpg"):             url +=".jpg"     return url  u in ["http://imgur.com/cuv9oau","http://www.google.com/search?q=http://imgur"]:     print fiximgurlinks(u) 

gives:

>>> http://i.imgur.com/cuv9oau.jpg >>> http://www.google.com/search?q=http://imgur