Python 3.4.3 - How to save a itertools.permutations list usable?

Question

i've tried many solutions to my problem, but I haven't find a solution yet.

import itertools

a = ['car','boat','plane']
b = list(itertools.permutations(a,))
print(b)

It gives this list when printed.

[('car', 'boat', 'plane'), ('car', 'plane', 'boat'), ('boat', 'car', 'plane'), ('boat', 'plane', 'car'), ('plane', 'car', 'boat'), ('plane', 'boat', 'car')]

But this isn't usable to me. I need something like that:

car boat plane
car plane boat
boat car plane
boat plane car
plane car boat
plane boat car

Space between words, no comma and 1 per line.

This was just a sample, because I have phrases with 20 words each and I need to make this with each one.

Now, just a real sample what I have to do.

import itertools
'phrase What are you doing to this cat?'
a = ['what','are','you','doing','to','this','cat?']
b = list(itertools.permutations(a,))
print(b)

The result will be a monster.

Answer 1

If you want to produce that actual string you have described you can do it with two join calls

'\n'.join(' '.join(r) for r in b)

The inner join concatenates the elements of each row with a ' ' separating them, the outer join then concatenates the rows with '\\n' between them. You can print the above directly or store it in a variable

Answer 2

You simply need to format it a bit. Join the items with a space, and separate them with a newline.

print(*(' '.join(item) for item in itertools.permutations(a,)), sep='\n')

Alternatively:

for item in itertools.permutations(a,):
    print(' '.join(item))

Answer 3

Just unpack the tuples returned by itertools.permutations(a,) and a for loop:

import itertools
a = 'what are you doing to this cat?'.split()
for permutation in itertools.permutations(a,):
    print(*permutation)

Using .split() on the phrase will make it easier to change out the sentence.

Answer 4

pprint.pprint is often useful for inspecting data. It doesn't give you precisely the form you want in this case, but it does give a useful form.

Code:

import itertools
from pprint import pprint

a = ['car','boat','plane']
b = list(itertools.permutations(a,))
pprint(b)

Result:

[('car', 'boat', 'plane'),
 ('car', 'plane', 'boat'),
 ('boat', 'car', 'plane'),
 ('boat', 'plane', 'car'),
 ('plane', 'car', 'boat'),
 ('plane', 'boat', 'car')]

Answer 5

You just need to do a string join with ',' for each element of each record from itertools.permutations, then join each record together with '\\n'. Here it is with a generator expression:

import itertools

a = ['car','boat','plane']
b = itertools.permutations(a)
s = '\n'.join((','.join(permutation) for permutation in b))
print(s)