For Repeating code many numbers of time we use loops

While Loop:

While loops execute a block of code until a block of code evaluates to true

def main():
    x = 0
    # define a while loop
    while(x<5):
        print(x)

def main():

x = 0

# define a while loop

while(x<5):

print(x)

for x in range(1,10):
    if(x%2 == 0):continue
    print(x)

for x in range(1,10):

if(x%2 == 0):continue

print(x)

x= x+1

if __name__ == ‘__main__’:
main()

0
1
2
3
4

For loop

# define a for loop
for x in range(1,6):
    print(x)

# define a for loop

for x in range(1,6):

print(x)

Output
1
2
3
4
5

- Python loops work somewhat different from other programming languages
- We define a range function to 1,6 to which it will iterate
- Here you note 6 that is the last number is not inclusive of the result. So the end number is not included in the range

Python loops with a list

months = ["jan","feb","march","april"]
for m in months:
    print(m)

months = ["jan","feb","march","april"]

for m in months:

print(m)

jan
feb
march
april

Break and continue Statement

for x in range(1,10):
    if(x==5):break
    print(x)

for x in range(1,10):

if(x==5):break

print(x)

1
2
3
4
When a value of x reaches 5 it simply breaks the loop and comes out of the loop.

Continue: skips the rest of the loop for that particular iteration

for x in range(1,10):
    if(x%2 == 0):continue
    print(x)

for x in range(1,10):

if(x%2 == 0):continue

print(x)

Output:

1
3
5
7
9

In the example here if x%2 == 0 it will skip the rest part of loop and continue with next value.

Using enumerate() function

We can use the enumerate() function to get index

Noramally for loop in python does not have key index value like any other programming language. But if we need key value pair we can use enumerate function

months = ["jan", "feb", "march", "april"]
for i,m in enumerate(months):
    print(i, m)

months = ["jan", "feb", "march", "april"]

for i,m in enumerate(months):

print(i, m)

Output:
(0, ‘jan’)
(1, ‘feb’)
(2, ‘march’)
(3, ‘april’)

This function will return the index and value pair