python - How to change list numbers -

i have list of numbers follows:

given = [[0,5,4,9,0],          [2,1,4,9,9]] 

i have change numbers follows:

0>>0 1>>1 2>>2 3>>3 4>>3 5>>4 9>>5 

or l1 l2.

l1 = [0,1,2,3,4,5,9] l2 = [0,1,2,3,3,4,5] 

expected answer is:

ans = [[0,4,3,5,0],        [2,1,3,5,5]] 

how easy way of doing it?

my trial dirty:

given[given==4]=3 , on. 

i prefer numpy method.

use dictionary translator:

>>> given = [[0,5,4,9,0], ...          [2,1,4,9,9]] >>> translation = {4:3, 5:4, 9:5} >>> [[translation.get(x, x) x in sub] sub in given] [[0, 4, 3, 5, 0], [2, 1, 3, 5, 5]] 

you need supply mapping numbers change, because dict.get(key, default) return given default value if key not found.