CODEWITHSUNDEEP
pythonpython-2.7permutation
George
George

Reputation: 13

Create a list with all possible permutations from a know list of objects, but make the final list x in size

Lets say I have the following list: 

lst = [0,1,3,a,b,c]

I would like the final outcome to be all possible permutations of lst, but be 20 characters long.

I have looked and can only find examples that would create a final outcome that would be 6 or less in length.

Any ideas?

Upvotes: 0

Views: 1824

Answers (4)

Volatility
Volatility

Reputation: 32300

I think itertools.product is what you're looking for.

# A simple example
import itertools
lst = [0, 1]
print(list(itertools.product(lst, repeat=2)))
# [(0, 0), (0, 1), (1, 0), (1, 1)]

Note that itertools.product itself returns an itertools.product object, not a list.

# In your case
import itertools
lst = [0, 1, 3, a, b, c]
output = list(itertools.product(lst, repeat=20))

Upvotes: 3

namit
namit

Reputation: 6957

list(permutations(lst,x)) ; where lst is iterable (your input list) and x is the no of elements

for example:

In [8]: lst = [0, 1, 3, 'a', 'b', 'c']

In [9]: from itertools import permutations

In [10]: result=[list(permutations(lst,x)) for x in range(1,len(lst))]

Upvotes: 0

mgoffin
mgoffin

Reputation: 765

The problem is that permutations and combinations (if you use itertools) follow the definition that each result can only physically exist if it is of equal or lesser length than the originating list.

If you are suggesting that you want one of the valid results to be "013abc013abc013abc01", then you'll have to modify your list to just be 20 items long and be made up of those 6 values.

from itertools import permutations
i = [0,1,3,'a','b','c',0,1,3,'a','b','c',0,1,3,'a','b','c',0,1]
results = []
for a in permutations(i, 20):
    results.append(a)

Upvotes: 0

Navin
Navin

Reputation: 4107

Are you sure you want all permutations? Assuming you want to reuse characters (not a permutation) that would be a list with a length of 6^20.

If you want one string of length 20 built from characters in that list, this should do the job:

from random import choice
''.join(choice(chars) for _ in range(length))

Upvotes: 0

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