Extract columns from a 2 dimentional table

[Leyo]

hello everyone,

I struggle on this exercise:
define a function col(mat, j) allowing to retrieve a column of the matrix. For example col(M, 1) will return [2, 6, 10].

here's the matrix (list of list created with loops):
M = [[1, 2, 3, 4],
[5, 6, 7, 8],
[9, 10, 11, 12]]

so far I wrote:

def col(mat,j):
    for i in range(3):  #search lines
        for j in range(4): #search columns
            return M[:][j] #return all elements from i column
col(0,1)

Output:
[1, 2, 3, 4]

I don't understand what to do with the parameter mat
can you help me understand what's wrong with my code?

I use Python 3 and Jupyter Notebook

Thanks in advance,
Leyo

Larz60+ write Feb-22-2022, 04:56 PM:
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