search vs. match

7.2.5.3. search() vs. match()

Python offers two different primitive operations based on regular expressions: re.match() checks for a match only at the beginning of the string, while re.search() checks for a match anywhere in the string (this is what Perl does by default).

For example:

>>>

>>> re.match("c", "abcdef")    # No match
>>> re.search("c", "abcdef")   # Match
<_sre.SRE_Match object at ...>

Regular expressions beginning with '^' can be used with search() to restrict the match at the beginning of the string:

>>>

>>> re.match("c", "abcdef")    # No match
>>> re.search("^c", "abcdef")  # No match
>>> re.search("^a", "abcdef")  # Match
<_sre.SRE_Match object at ...>

Note however that in MULTILINE mode match() only matches at the beginning of the string, whereas using search() with a regular expression beginning with '^' will match at the beginning of each line.

>>>

>>> re.match('X', 'A\nB\nX', re.MULTILINE)  # No match
>>> re.search('^X', 'A\nB\nX', re.MULTILINE)  # Match
<_sre.SRE_Match object at ...>

>>> print(re.match(r"\d+", "123fasdf1234").group(0))
123
>>> print(re.match(r"\d+", "123fasdf1234").start())
0
>>> print(re.match(r"\d+", "123fasdf1234").end())
3