Python makes regular expressions available through the re
module.
Regular expressions are combinations of characters that are interpreted as rules for matching substrings. For instance, the expression 'amount\\D+\\d+'
will match any string composed by the word amount
plus an integral number, separated by one or more non-digits, such as: amount=100
, amount is 3
, amount is equal to: 33
, etc.
re.match(pattern, string, flag=0)
# Out: match pattern at the beginning of string or Nonere.search(pattern, string, flag=0)
# Out: match pattern inside string or Nonere.findall(pattern, string, flag=0)
# Out: list of all matches of pattern in string or []re.finditer(pattern, string, flag=0)
# Out: same as re.findall, but returns iterator objectre.sub(pattern, replacement, string, flag=0)
# Out: string with replacement (string or function) in place of patternprecompiled_pattern = re.compile(pattern, flag=0)
precompiled_pattern.match(string)
# Out: match at the beginning of string or Noneprecompiled_pattern.search(string)
# Out: match anywhere in string or Noneprecompiled_pattern.findall(string)
# Out: list of all matching substringsprecompiled_pattern.sub(string/pattern/function, string)
# Out: replaced string