Question

here is a scenario, I am checking if elements of A are present in B. while this code works, it takes a lot of time when I read through million of lines. The efficient way would be to make each list in A and B as dictionary and look if they are present in each other. But I am not able to think of a simple way to do dictionary lookup. That is for each key-value pair in dict A, I want to check if that key-value pair is present in dictB

A = [['A',[1,2,3]],['D',[3,4]],['E',[6,7]]]

B=  [['A',[1,2,3]],['E',[6,7]],['F',[8,9]]]

count = 0

for line in A:

  if len(line[1]) > 1:

     if line in B:

       count = count + 1

print count

Answer 1

1. convert the lists to tuples
2. convert the list of tuples to a set
3. intersect the two sets
4. print the length of the intersection

Example:

A = [['A',[1,2,3]],['D',[3,4]],['E',[6,7]]] 
B = [['A',[1,2,3]],['E',[6,7]],['F',[8,9]]]

A_set = set((a, tuple(b)) for a, b in A)
B_set = set((a, tuple(b)) for a, b in B)
print len(A_set & B_set)