CODEWITHSUNDEEP
pythonsplitlist-comprehension
coderoftheday
coderoftheday

Reputation: 2075

How to do `for line.split() in line:` as list comprehension

I'm trying to use python comprehension.

I have a list which is in the format:

name_a:surname_a
name_b:surname_b
name_c:surname_c

My code initially to split each pair in a line into its own variable was:

for lined in self.account:
    a, b = line.split(':')

I tried to use this comprehension, but it didn't seem to work:

(a,b) = [line.split(':') for line in self.account]

Upvotes: 1

Views: 474

Answers (1)

Querenker
Querenker

Reputation: 2365

As mentioned by @MattDMo the colons are missing in your list comprehension. If you add them, a additional problem will appear. If you print the list returned from the list comprehension, it will probably look like this:

[['name_a', 'surname_a\n'], ['name_b', 'surname_b\n'], ['name_c', 'surname_c\n']]

The problem is, that you can't assign it to two variables, because the list contains the same number of elements as lines in the file.

To get the desired result, you have to transpose the two dimensional list, for example by using zip and unpacking ('*'):

>>> with open('test_file.txt') as f:
...   (a, b) = zip(*[line.split(':') for line in f])
...
>>> a
('name_a', 'name_b', 'name_c')
>>> b
('surname_a\n', 'surname_b\n', 'surname_c\n')

Upvotes: 1

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