Python regular expressions matching within set

Question

While testing on http://gskinner.com/RegExr/ (online regex tester), the regex [jpg|bmp] returns results when either jpg or bmp exist, however, when I run this regex in python, it only return j or b. How do I make the regex take the whole word "jpg" or "bmp" inside the set ? This may have been asked before however I was not sure how to structure question to find the answer. Thanks !!!

Here is the whole regex if it helps

"http://www\S*(?i)\\.(jpg|bmp|png|gif|img|jng|jpeg|jpe|gif|giff)"

Its just basically to look for pictures in a url

Answer 1

Use (jpg|bmp) instead of square brackets.

Square brackets mean - match a character from the set in the square brackets.

Edit - you might want something like that: [^ ].*?(jpg|bmp) or [^ ].*?\.(jpg|bmp)

Answer 2

When you are using [] your are creating a character class that contains all characters between the brackets.

So your are not matching for jpg or bmp you are matching for either a j or a p or a g or a | ...

You should add an anchor for the end of the string to your regex

http://www\S*(?i)\\.(jpg|bmp|png|gif|img|jng|jpeg|jpe|gif|giff)$
          ^      ^^

if you need double escaping then every where in your pattern

http://www\\S*(?i)\\.(jpg|bmp|png|gif|img|jng|jpeg|jpe|gif|giff)$

to ensure that it checks for the file ending at the very end of the string.