CODEWITHSUNDEEP
pythonpython-3.xlist
Simor Atias
Simor Atias

Reputation: 47

Generate lists from matrix with the same index

I have a matrix that has 'N' lists, each list has 3 strings, that each string has 'M' characters.

For example, N=3 (3 lists) and M=3 (all the strings are 3 characters):

M = [['123', '456', '789'], ['abc', 'def', 'ghi'], ['ABC', 'DEF', 'GHI']]

I need to generate lists of the same index values, let me show you the output:

['1aA', '2bB', '3cC']
['1aD', '2bE', '3cF']
['1aG', '2bH', '3cI']

['1dA', '2eB', '3fC']
['1dD', '2eE', '3fF']
['1dG', '2eH', '3fI']

['1gA', '2hB', '3iC']
['1gD', '2hE', '3iF']
['1gG', '2hH', '3iI']

['4aA', '5bB', '6cC']
['4aD', '5bE', '6cF']
['4aG', '5bH', '6cI']

['4dA', '5eB', '6fC']
['4dD', '5eE', '6fF']
['4dG', '5eH', '6fI']

['4gA', '5hB', '6iC']
['4gD', '5hE', '6iF']
['4gG', '5hH', '6iI']

['7aA', '8bB', '9cC']
['7aD', '8bE', '9cF']
['7aG', '8bH', '9cI']

['7dA', '8eB', '9fC']
['7dD', '8eE', '9fF']
['7dG', '8eH', '9fI']

['7gA', '8hB', '9iC']
['7gD', '8hE', '9iF']
['7gG', '8hH', '9iI']

Do you have any suggestion how should I do it?

Upvotes: 3

Views: 49

Answers (2)

Devesh Kumar Singh
Devesh Kumar Singh

Reputation: 20500

One way to approach this problem is to take the cartesian product of all strings using itertools.product, and for each product, pick the items at the same index and make a string out of them using zip

from itertools import product

M = [['123', '456', '789'], ['abc', 'def', 'ghi'], ['ABC', 'DEF', 'GHI']]

output = []

#Take product of all elements
for lst in product(*M):

    #Take the characters at the same index and make a string out of them via zip
    res = [''.join(item) for item in zip(*lst)]

    #Append that list to final output
    output.append(res)

for item in output:
    print(item)

The output will be

['1aA', '2bB', '3cC']
['1aD', '2bE', '3cF']
['1aG', '2bH', '3cI']
['1dA', '2eB', '3fC']
['1dD', '2eE', '3fF']
['1dG', '2eH', '3fI']
['1gA', '2hB', '3iC']
['1gD', '2hE', '3iF']
['1gG', '2hH', '3iI']
['4aA', '5bB', '6cC']
['4aD', '5bE', '6cF']
['4aG', '5bH', '6cI']
['4dA', '5eB', '6fC']
['4dD', '5eE', '6fF']
['4dG', '5eH', '6fI']
['4gA', '5hB', '6iC']
['4gD', '5hE', '6iF']
['4gG', '5hH', '6iI']
['7aA', '8bB', '9cC']
['7aD', '8bE', '9cF']
['7aG', '8bH', '9cI']
['7dA', '8eB', '9fC']
['7dD', '8eE', '9fF']
['7dG', '8eH', '9fI']
['7gA', '8hB', '9iC']
['7gD', '8hE', '9iF']
['7gG', '8hH', '9iI']

Or a one-liner using list comprehension

output = [[''.join(item) for item in zip(*lst)] for lst in product(*M)]

Upvotes: 2

Adam.Er8
Adam.Er8

Reputation: 13413

using itertools.product() and zip() we can group the elements we need together, then generate all the particular strings ("cell contents") from them, and then just "reshape" them into a matrix.

try this:

from itertools import product

M = [['123', '456', '789'], ['abc', 'def', 'ghi'], ['ABC', 'DEF', 'GHI']]

nums = zip(*M[0])
lowers = zip(*M[1])
uppers = zip(*M[2])
groups = zip(nums, lowers, uppers)
strings = [[''.join(chars) for chars in [*product(*g)]] for g in groups ]
string_chunks = [list(chunk) for chunk in zip(*strings)]
result = [string_chunks[i:i + len(M)] for i in range(0, len(string_chunks), len(M))]
for matrix in result:
    for row in matrix:
        print(row)
    print()

Output:

['1aA', '2bB', '3cC']
['1aD', '2bE', '3cF']
['1aG', '2bH', '3cI']

['1dA', '2eB', '3fC']
['1dD', '2eE', '3fF']
['1dG', '2eH', '3fI']

['1gA', '2hB', '3iC']
['1gD', '2hE', '3iF']
['1gG', '2hH', '3iI']

['4aA', '5bB', '6cC']
['4aD', '5bE', '6cF']
['4aG', '5bH', '6cI']

['4dA', '5eB', '6fC']
['4dD', '5eE', '6fF']
['4dG', '5eH', '6fI']

['4gA', '5hB', '6iC']
['4gD', '5hE', '6iF']
['4gG', '5hH', '6iI']

['7aA', '8bB', '9cC']
['7aD', '8bE', '9cF']
['7aG', '8bH', '9cI']

['7dA', '8eB', '9fC']
['7dD', '8eE', '9fF']
['7dG', '8eH', '9fI']

['7gA', '8hB', '9iC']
['7gD', '8hE', '9iF']
['7gG', '8hH', '9iI']

Upvotes: 0

Related Questions