[Tutor] Examples of "With....As Statement" in Python

[mariocatch]

On Tue, Jul 10, 2012 at 11:25 AM, Mark Lawrence <breamoreboy at yahoo.co.uk>wrote:

> On 10/07/2012 15:58, James Bell wrote:
>
>> I'm attempting to learn how to use the "with....as" statement in python.
>>
>> I've read the documentation and also a few tutorials but I still cannot
>> understand the concept. or how this is normally used. Can someone please
>> write an example or 2 of simple ways to use the "with statement".
>>
>> I understand in java the try...catch...finally block so maybe someone can
>> point out the relationship between them.
>>
>> thanks.
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>>
> You're not the only one, see this http://effbot.org/zone/python-**
> with-statement.htm <http://effbot.org/zone/python-with-statement.htm>
>
> --
> Cheers.
>
> Mark Lawrence.
>
>
>
> ______________________________**_________________
> Tutor maillist  -  Tutor at python.org
> To unsubscribe or change subscription options:
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>

The 'with' statement (
http://docs.python.org/tutorial/inputoutput.html#methods-of-file-objects).
'with' is not like a try/catch/finally. It is more like a using in .NET.
It's simply a way for you to create an instance of a disposable object, and
have it automatically cleaned up for you at the end of the 'with' statement.
Consider the following file usage:
f = open('test.txt', 'r')
f.read()
f.close()
Imagine if I forgot to close the file handler 'f'? Instead of worrying
about that, you can let python handle it for you:
with open('test.txt, 'r') as f:
f.read()
Now, when the 'with' statement ends, it will automatically dispose the file
object 'f' and close the stream for you.
-Mario
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