Question

I am new to Python, and I am trying to check whether a pair [a,b] exists in a list l=[[a,b],[c,d],[d,e]]. I searched many questions, but couldn’t find precise solution. Please can someone tell me the right and shortest way of doing it?

when i run :

a=[['1','2'],['1','3']]
for i in range(3):
    for j in range(3):
        if [i,j] in a:
            print a

OUTPUT IS BLANK

how to achieve this then?

Answer 1

The code does not work because '1' != 1 and, consequently, ['1','2'] != [1,2]
If you want it to work, try:

a=[['1','2'],['1','3']]
for i in range(3):
    for j in range(3):
        if [str(i), str(j)] in a: # Note str
            print a

(But using in or sets as already mentioned is better)