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check if regeular expression has results

Hi,
I'm looking for the best way to check if regular expression return
true (it's mean - there is a match). for example, i want "if" that
check if this regular expression: .*born.*to.* has a match.

What's the way to do that simply?

Thanks a lot,
Shahar.

Aug 9 '07 #1
3 1104
On Thu, 09 Aug 2007 05:58:22 -0700, shahargs wrote:
I'm looking for the best way to check if regular expression return
true (it's mean - there is a match). for example, i want "if" that
check if this regular expression: .*born.*to.* has a match.

What's the way to do that simply?
Simply use an ``if`` on the result of the search or match. If the regular
expression doesn't match `None` is returned, which is `False` in a boolean
context, otherwise a match object is returned, which is `True` in a
boolean context.

Ciao,
Marc 'BlackJack' Rintsch
Aug 9 '07 #2
On 8/9/07, sh******@gmail. com <sh******@gmail .comwrote:
Hi,
I'm looking for the best way to check if regular expression return
true (it's mean - there is a match). for example, i want "if" that
check if this regular expression: .*born.*to.* has a match.

What's the way to do that simply?
How about

import re
re.match(".*bor n.*to", "This is a test")
re.match(".*bor n.*to.*", "This test was born so that it worked too.")

(Try these at the python prompt)

The first call to 're.match()' returns 'None' which will fail an if
test. The second one returns a match object, which evaluates to TRUE
in an if test.

--wpd
Aug 9 '07 #3
sh******@gmail. com wrote:
Hi,
I'm looking for the best way to check if regular expression return
true (it's mean - there is a match). for example, i want "if" that
check if this regular expression: .*born.*to.* has a match.

What's the way to do that simply?
A failed match returns None. A successful match returns a match object.
So the easiest way to check for a successful match is

pat = re.compile(...)
....
m = pat.match(some_ string)
if m:
... you got a match ...
else:
... you didn't ...

regards
Steve
--
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Aug 9 '07 #4

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