Assignment-in-conditional

[xamdam]

I am not sure if this came up before, but I would love to have an
'assignment-in-conditional' form in python, e.g

pat = re.compile('something')

if m = pat.match(s):
m.group(1)

Of course there is some concern about accidentally using '=' instead of
'=='. One possible solution is to do what the 'with' statement does:

if pat.match(s) as m:
...

a little ugly but not too much worse that with itself..

what do you guys think?

- max

 

[Fredrik Lundh]

I am not sure if this came up before, but I would love to have an
'assignment-in-conditional' form in python, e.g

it's a FAQ, so it has probably come up before:

http://pyfaq.infogami.com/why-can-t-i-use-an-assignment-in-an-expression

</F>

 

[Neil Cerutti]

it's a FAQ, so it has probably come up before:

http://pyfaq.infogami.com/why-can-t-i-use-an-assignment-in-an-expression

Python saves me from ever making the assignment-as-conditional
mistake, but I invented the conditional-as-assignment mistake to
compensate.

 

[Georg Brandl]

I am not sure if this came up before, but I would love to have an
'assignment-in-conditional' form in python, e.g

pat = re.compile('something')

if m = pat.match(s):
m.group(1)

Of course there is some concern about accidentally using '=' instead of
'=='. One possible solution is to do what the 'with' statement does:

if pat.match(s) as m:
...

a little ugly but not too much worse that with itself..

what do you guys think?

It has been proposed before (a few times even), and Guido doesn't like it.

Georg

 

[xamdam]

Thanks for the FAQ, and for the 'casm

What do you think about using alternative syntax (something like 'as')

- max

 

[Simon Forman]

Thanks for the FAQ, and for the 'casm

What do you think about using alternative syntax (something like 'as')

- max

There are two recipies in the cookbook for doing this:

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/202234
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66061

HTH,
~Simon