for Loop (JNNC Technologies)

Figure – for loop Flowchart:

Syntax:

for iterating_var in sequence:
   //execute your code

Example 01:

#!/usr/bin/python

for x in range (0,3) :
    print 'Loop execution %d' % (x)

Output:

Loop execution 0
Loop execution 1
Loop execution 2

Example 02:

#!/usr/bin/python

for letter in 'TutorialsCloud': 
   print 'Current letter is:', letter

Output:

Current letter is : T
Current letter is : u
Current letter is : t
Current letter is : o
Current letter is : r
Current letter is : i
Current letter is : a
Current letter is : l
Current letter is : s
Current letter is : C
Current letter is : l
Current letter is : o
Current letter is : u
Current letter is : d

while Loop

The graphical representation of the logic behind while looping is shown below:

Figure – while loop Flowchart:

Syntax:

while expression:
   //execute your code

Example:

#!/usr/bin/python

#initialize count variable to 1
count =1

while count < 6 :
    print count
    count+=1
#the above line means count = count + 1

Output:

1
2
3
4
5

Nested Loops

Syntax:

for iterating_var in sequence:
   for iterating_var in sequence:
      //execute your code
         //execute your code

Example:

for g in range(1, 6):
    for k in range(1, 3):
        print '%d * %d = %d' % ( g, k, g*k)

Output:

1 * 1 = 1
1 * 2 = 2
2 * 1 = 2
2 * 2 = 4
3 * 1 = 3
3 * 2 = 6
4 * 1 = 4
4 * 2 = 8
5 * 1 = 5
5 * 2 = 10