4.2.2 Matching vs. Searching

















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4.2.2 Matching vs. Searching



Python offers two different primitive operations based on regular
expressions: match and search. If you are accustomed to Perl's
semantics, the search operation is what you're looking for. See the
search() function and corresponding method of compiled
regular expression objects.


Note that match may differ from search using a regular expression
beginning with "^": "^" matches only at the
start of the string, or in MULTILINE mode also immediately
following a newline. The ``match'' operation succeeds only if the
pattern matches at the start of the string regardless of mode, or at
the starting position given by the optional pos argument
regardless of whether a newline precedes it.



re.compile("a").match("ba", 1) # succeeds
re.compile("^a").search("ba", 1) # fails; 'a' not at start
re.compile("^a").search("\na", 1) # fails; 'a' not at start
re.compile("^a", re.M).search("\na", 1) # succeeds
re.compile("^a", re.M).search("ba", 1) # fails; no preceding \n









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