Comparing Python nested lists

Question

I have two nested lists, each nested list containing two strings e.g.: ``` list 1 [('EFG', '[3,4,5]'), ('DEF', '[2,3,4]')] and list 2 [('DEF', '[2,3,4]'), ('FGH', '[4,5,6]')] ``` I would like to compare the two lists and recover those nested lists which are identical with each other. In this case only `('DEF','[2,3,4]')` would be returned. The lists could get long. Is there an efficient way to do this?

Accepted Answer

If the lists only contain string tuples, then the easiest way to do it is using sets intersection (&):

```
>>> set([('EFG', '[3,4,5]'), ('DEF', '[2,3,4]')]) & set([('DEF', '[2,3,4]'), ('FGH', '[4,5,6]')])
set([('DEF', '[2,3,4]')])
```

Comparing Python nested lists

Solution

Problem