Shortcut to solve Questions related to for loop.

1.Introduction to For loop
For loop is used to iterate over a sequence. With the help of for loop all the items present in the sequence are accessed one by one.

2.Trick to solve nested loop questions in a easy way
Let first for loop condition to be Days & other loop conditions to be sessions. That basically means that a student has to sit in all sessions everyday.

For example-

for i in range(3):
 for j in range(6):
   print(j, end=' ')

TRICK TO SOLVE ABOVE QUESTION:
Let i = Days(Monday, Tuesday, etc..) &
j = Sessions(Mathematics, Science, etc..)
range for i = (0,1,2)
range for j = (0,1,2,3,4,5)
Iteration1:
i=0, condition become True and loop will be connected
Day will be Monday. There are 6 sessions in j and a student has to sit in all sessions every day.
So, result will come to be 0 1 2 3 4 5
Iterations3:
i = 2, condition become True and day will be Wednesday. Result = 0 1 2 3 4 5
Final output
0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5

Example 2:

my_string =['Mathematics','Science','History']
for i in range(len(my_string)):
  for x in range(4):
    print(x, end=(' '))

Explanation:
Iteration1:
Range for i = (0,1,2)
Range for x = (0,1,2,3)
i = 0,Day 1 i.e Monday ,we have to sit in all sessions So, output become 0 1 2 3
Iteration3:
i = 2, Day 3 is Wednesday and after sitting in all sessions, output comes out to be 0 1 2 3.
Final output
0 1 2 3 0 1 2 3 0 1 2 3