yet another list comprehension question

[Ross]

I'm trying to set up a simple filter using a list comprehension. If I
have a list of tuples, a = [(1,2), (3,4), (5,None), (6,7), (8, None)]
and I wanted to filter out all tuples containing None, I would like to
get the new list b = [(1,2), (3,4),(6,7)].

I tried b = [i for i in a if t for t in i is not None] but I get the
error that "t is not defined". What am I doing wrong?

 

[Chris Rebert]

I'm trying to set up a simple filter using a list comprehension. If I
have a list of tuples, a = [(1,2), (3,4), (5,None), (6,7), (8, None)]
and I wanted to filter out all tuples containing None, I would like to
get the new list b = [(1,2), (3,4),(6,7)].

b = [tup for tup in a if None not in tup]

Cheers,
Chris

 

[Ross]

I'm trying to set up a simple filter using a list comprehension. If I
have a list of tuples, a = [(1,2), (3,4), (5,None), (6,7), (8, None)]
and I wanted to filter out all tuples containing None, I would like to
get the new list b = [(1,2), (3,4),(6,7)].

b = [tup for tup in a if None not in tup]

Cheers,
Chris
--http://blog.rebertia.com

Thanks I feel retarded sometimes.

 

[CTO]

I'm trying to set up a simple filter using a list comprehension. If I
have a list of tuples, a = [(1,2), (3,4), (5,None), (6,7), (8, None)]
and I wanted to filter out all tuples containing None, I would like to
get the new list b = [(1,2), (3,4),(6,7)].

try this:

b = [i for i in a if None not in i]

I tried b = [i for i in a if t for t in i is not None]   but I get the
error that "t is not defined". What am I doing wrong?

You've got a "for" and an "if" backwards. t isn't defined when the if
tries to evaluate it.

 

[Snorri H]

I'm trying to set up a simple filter using a list comprehension. If I
have a list of tuples, a = [(1,2), (3,4), (5,None), (6,7), (8, None)]
and I wanted to filter out all tuples containing None, I would like to
get the new list b = [(1,2), (3,4),(6,7)].

I tried b = [i for i in a if t for t in i is not None] but I get the
error that "t is not defined". What am I doing wrong?

Works as well:
filter(lambda x:not None in x, your_list)

 

[Arnaud Delobelle]

I'm trying to set up a simple filter using a list comprehension. If I
have a list of tuples, a = [(1,2), (3,4), (5,None), (6,7), (8, None)]
and I wanted to filter out all tuples containing None, I would like to
get the new list b = [(1,2), (3,4),(6,7)].

I tried b = [i for i in a if t for t in i is not None] but I get the
error that "t is not defined". What am I doing wrong?

Works as well:
filter(lambda x:not None in x, your_list)

^^^^^^^^^^^^^
This is usually spelt 'None not in x'.

 

[David Robinow]

ls = [(1,2), (3,4), (5, None), (6,7), (8, None)]
[(x,y) for (x,y) in ls if y]

[(1, 2), (3, 4), (6, 7)]

Nope. That filters out 0 as well as None. Not what the OP asked for.

 

[namekuseijin]

ls = [(1,2), (3,4), (5, None), (6,7), (8, None)]
[(x,y) for (x,y) in ls if y]

[(1, 2), (3, 4), (6, 7)]

Nope. That filters out 0 as well as None. Not what the OP asked for.

True. I'm still a C programmer at heart I guess. ah, the flexibility
of 0...

 

[namekuseijin]

This seems to work for any length tuples :

a = [(1,2), (3,4, 'goes'), (5,None), (6,7, 8, 'as', None), (8, None),
(9, 0)]
[tup for tup in a if not [e for e in tup if e == None]]

[(1, 2), (3, 4, 'goes'), (9, 0)]

Why that extra "for"? KISS

a = [(1,2), (3,4, 'goes'), (5,None), (6,7, 8, 'as', None), (8, None), (9, 0)] [(1, 2), (3, 4, 'goes'), (5, None), (6, 7, 8, 'as', None), (8, None), (9, 0)]
[t for t in a if None not in t]

[(1, 2), (3, 4, 'goes'), (9, 0)]

"in" works perfectly well for any sequence, including strings.