Re: [Tutor] What the difference between the two RE?

2012-02-09 Thread Christian Witts 

On 2012/02/09 09:44 AM, daedae11 wrote:
However, re.match(hello, And they said hello ) will also return 
None. So And they said hello also won't be matched by the regex 
pattern hello.


daedae11
*From:* Christian Witts mailto:cwi...@compuscan.co.za
*Date:* 2012-02-09 15:16
*To:* daedae11 mailto:daeda...@126.com
*CC:* turor_python mailto:tutor@python.org
*Subject:* Re: [Tutor] What the difference between the two RE?
On 2012/02/09 08:15 AM, daedae11 wrote:

import re
re.match(^hello, hello)
re.match(hello, hello)
Please give a string that matches RE ^hello but does not match RE 
hello, or matches RE hello but does not match RE ^hello.


daedae11


___
Tutor maillist  -Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
The caret ^ means At the beginning of the line so 'And they said 
hello' will not be matched by the regex pattern '^hello'.


The docs are pretty good on the module
http://docs.python.org/library/re.html
http://docs.python.org/howto/regex.html
--

Christian Witts
Python Developer
//

--

From the docs http://docs.python.org/library/re.html#re.match
Note: If you want to locate a match anywhere in string, use search() 
instead.

--

Christian Witts
Python Developer
//
___
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor

Re: [Tutor] What the difference between the two RE?

2012-02-09 Thread Steven D'Aprano 

daedae11 wrote:

import re
re.match(^hello, hello)
re.match(hello, hello)

Please give a string that matches RE ^hello but does not match RE
hello, or matches RE hello but does not match RE ^hello.


re.match always matches the beginning of the string, so

re.match(^hello, something)
re.match(hello, something)

are identical.

re.search will search anywhere in the string, not just the beginning, so:

re.search(^hello, something)

means find the beginning of the string followed by h e l l o

while

re.search(hello, something)

means find h e l l o anywhere in the string.



--
Steven
___
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor

Re: [Tutor] What the difference between the two RE?

2012-02-09 Thread Brett Ritter 
On Thu, Feb 9, 2012 at 1:15 AM, daedae11 daeda...@126.com wrote:
 import re
 re.match(^hello, hello)
 re.match(hello, hello)

 Please give a string that matches RE ^hello but does not match RE hello,
 or matches RE hello but does not match RE ^hello.

In addition to the other answers, it's important to note that nothing
in these REs require it to be a word. So both of the above will
match the hello in hellonwheels for example.

-- 
Brett Ritter / SwiftOne
swift...@swiftone.org
___
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor

[Tutor] What the difference between the two RE?

2012-02-08 Thread daedae11 
import re
re.match(^hello, hello)
re.match(hello, hello)

Please give a string that matches RE ^hello but does not match RE hello, or 
matches RE hello but does not match RE ^hello.




daedae11___
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor

Re: [Tutor] What the difference between the two RE?

2012-02-08 Thread Christian Witts 

On 2012/02/09 08:15 AM, daedae11 wrote:

import re
re.match(^hello, hello)
re.match(hello, hello)
Please give a string that matches RE ^hello but does not match RE 
hello, or matches RE hello but does not match RE ^hello.


daedae11


___
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
The caret ^ means At the beginning of the line so 'And they said 
hello' will not be matched by the regex pattern '^hello'.


The docs are pretty good on the module
http://docs.python.org/library/re.html
http://docs.python.org/howto/regex.html
--

Christian Witts
Python Developer
//
___
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor

Re: [Tutor] What the difference between the two RE?

2012-02-08 Thread Göran Törnquist 

On 2012-02-09 08.16, Christian Witts wrote:

On 2012/02/09 08:15 AM, daedae11 wrote:

import re
re.match(^hello, hello)
re.match(hello, hello)
Please give a string that matches RE ^hello but does not match RE 
hello, or matches RE hello but does not match RE ^hello.


daedae11


___
Tutor maillist  -Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
The caret ^ means At the beginning of the line so 'And they said 
hello' will not be matched by the regex pattern '^hello'.


The docs are pretty good on the module
http://docs.python.org/library/re.html
http://docs.python.org/howto/regex.html
--

Christian Witts
Python Developer



This is also a good source of information for regexp patterns in general:
http://www.regular-expressions.info/

Göran Törnquist
Usertime
___
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor