Running through two arrays python

Question

I'm trying to loop through two lists and create tuple with it and then return list.

m = re.findall(reg, request) //List of all names from website
i = re.findall(reg2, request) //job title.

lst = []
for name in m:
    for job in i: #<======= Can't access name after this point
        if name and job:
            tub = (name, job)
            if tub not in lst:
                lst.append(tub)
        elif name:
            tub = (name, None)
            if tub not in lst:
                lst.append(tub)

print(lst)
return lst

With this input it is:

print(m) -> ['Name Nameson']
print(i) -> []

But it seem like i can't access the name variable in the inner loop. If set print(name) in the outer loop it shows but not in the inner. So the return is always [].

I'm new to python what I'am i doing wrong here?

Can you show print i and print m outputs. And the rest of your code if possible.. there should be more because you have a return without a function... — sihrc
– sihrc, Commented Jul 29, 2013 at 22:53
your i is empty!! It is not going to enter the second loop.. — v2b
– v2b, Commented Jul 29, 2013 at 22:58

Joran Beasley · Accepted Answer · 2013-07-29 22:58:09Z

1

for i in range(10):
    for j in range(10):
        print i,j

you are doing something wrong ... its hard to say more without seeing your input ... in your code your i = []

so

for item in []:
   print "this will never print"

edited Jul 29, 2013 at 22:58

answered Jul 29, 2013 at 22:52

Joran Beasley

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Comments

Lochemage · Accepted Answer · 2013-07-29 23:00:44Z

1

Your output says it all, list i is an empty list, so your nested job loop won't event loop once. So it isn't that 'name' isn't being carried into the nested loop, it's that you aren't even going into the nested loop block in the first place.

answered Jul 29, 2013 at 23:00

Lochemage

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FastTurtle · Accepted Answer · 2013-07-29 23:03:07Z

1

I like to use functions in itertools when working with permutations of iterables. itertools.product should do what you want.

>>> from itertools import product

>>> l1 = [1, 2, 3, 4]
>>> l2 = ['a', 'b', False, 'd']

>>> list((x, y) if y else (x, None) for x, y in product(l1, l2) if x)

[(1, 'a'), (1, 'b'), (1, None), (1, 'd'), (2, 'a'), (2, 'b'), (2, None),
 (2, 'd'), (3, 'a'), (3, 'b'), (3, None), (3, 'd'), (4, 'a'), (4, 'b'),
 (4, None), (4, 'd')]

edited Jul 29, 2013 at 23:03

answered Jul 29, 2013 at 22:53

FastTurtle

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2 Comments

FastTurtle Over a year ago

Thanks for pointing that out, fixed the code to better reflect the question.

Joran Beasley Over a year ago

and a solid answer at that (+1 for itertools)

tohava · Accepted Answer · 2013-07-29 22:54:13Z

0

Why not use list comprhension and sets instead?

list(set([(name, job) for name in m for job in i]))

answered Jul 29, 2013 at 22:54

tohava

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