Find indices of a value in 2d matrix

Question

I have a matrix of the form,

mymatrix=[[1,2,3],[4,5,6],[7,8,9]]

I want to the get the index of, say for example, 9 which is at (2,2).

Answer 1

If you want all of the locations that the value appears at, you can use the following list comprehension with val set to whatever you're searching for

[(index, row.index(val)) for index, row in enumerate(mymatrix) if val in row]

for example:

>>> mymatrix=[[1,2,9],[4,9,6],[7,8,9]]
>>> val = 9
>>> [(index, row.index(val)) for index, row in enumerate(mymatrix) if val in row]
[(0, 2), (1, 1), (2, 2)]

EDIT

It's not really true that this gets all occurrences, it will only get the first occurrence of the value in a given row.