Python3 for Loop

Python For Loop

for Loop:

        The for loop is used to iterate over a sequence (list, tuple, string) or other iterable objects.

     Iterating over a sequence  is called traversal.

Syntax:

  

       for element in sequence:

     

            body of for

Here, elements is the variable that takes the value of the item inside the sequence on each iteration.

Loop continues until we reach the last item in the sequence.

Flow chart:

                                      

Eg:

       lst=[10,20,30,40,50]

       product=1

       for ele in lst: 

             product*=ele

       print("product is: {}".format(product))

output:: product is: 12000000

for more info :

 https://youtu.be/yaqMSBr_NCU

range() function :

           We can generate a sequence of numbers using range() function. range(10) will generate numbers from 0 to 9(10 numbers).

Eg:

       for i in range(10):

             print(i)

output::   0

               1
               2

               3

               4

               5

               6

               7

               8

               9 

Eg:

       for i in range(1,16,2): 

            print(i)

output:: 1

               3

               5

               7

               9

               11

               13

               15

Eg:

       lst=["Ram", "Bharath", "Krishna", "Lakshman", "dharma raj"]

       for index in range(len(lst)):

             print(lst[index])

output::  Ram

                Bharath

                Krishna

                Lakshman

               dharma raj

for loop with else:

      A for loop can have an optional else block as well. The else part is executed if the items in the sequence used in for loop exhausts.

*  break statement can be used to stop a for loop, in such case, the else part is ignored.

Hence, a for loop's else part runs if no break occur.

Eg:

   

       nums=[1,3,5]

       for item in nums:

            print(item)

       else:

            print("no item left in the list")

output: 1

             3

             5

             no item left in the list

 Eg:

       nums=[1,2,3]

       for item in nums:

             print(item)

             if item%2==0:

                 break

       else:

            print("no item left in the list")

output::  1

                2

Python program to display all prime numbers within an interval:

       i=10

       j=50

       print("prime numbers between {} and {} are: ".format(i,j))

       for num in range(i,j+1):

              if num>1:

                   isdivisible=False;

                   for index in range(2,num):

                         if num%index==0:

                              isdivisible=True;

                   if not isdivisible:

                        print(num);

output:: prime numbers between 10 and 50 are: 

             11

             13

             17

             19

             23

             29

             31

             37

             41

             43

             47