Why output is 7

Question

a = [(1,0)[2,3,1],{1:'a',4:'b'}]
lst = []
for n in a:
lst.extend(n)
print(len(lst))

#output

7

Answer 1

Because its 7 elements in list
1 0 2 3 1 a b

Answer 2

You could have checked yourself as well ,print is a very useful function ,if you don't understand something ,using print to see the output after a step and try to understand it

Like in the example above place a print(lst) statement after lst.extend