Regular expressions in Python

regex.md

Regex in Python

1. Use the regex library by typing

   import re

2. A regex pattern looks like this:

   r"<pattern>"
   r"(\d{4}(\-?)){4}"

3. re.match() vs re.search()?

   1. re.match() only checks from the beginning
   2. re.search() checks anywhere in the string
   3. Example:

      >>> re.match("c", "abcdef")    # No match
      >>> re.search("c", "abcdef")   # Match

   4. https://docs.python.org/3/library/re.html#search-vs-match

4. re.match() returns the first occurrence, while re.findall() returns all the matches

5. re.sub(A, B, target_string) replaces A with B in target_string