how to remove an element from a nested list?

Question

if i have an nested list such as:

m=[[34,345,232],[23,343,342]]

if i write m.remove(345) it gives an error message saying elem

Answer 1

In [5]: m=[[34,345,232],[23,343,342]]

In [7]: [[ subelt for subelt in elt if subelt != 345 ] for elt in m] 
Out[7]: [[34, 232], [23, 343, 342]]

Note that remove(345) only removes the first occurrance of of 345 (if it exists). The above code removes all occurrances of 345.