Example of the use of nested loops in Python.

The Python programming language allows nesting one loop inside another. A few examples will be presented below to illustrate this concept.
grammatical

The syntax for nested loop statements in Python is as follows:

for iterating_var in sequence:
  for iterating_var in sequence:
   statements(s)
  statements(s)

The Python programming language allows nesting one loop inside another. A few examples will be presented below to illustrate this concept.
grammatical

The syntax for nested loop statements in Python is as follows:

for iterating_var in sequence:
  for iterating_var in sequence:
   statements(s)
  statements(s)

The syntax of a nested while loop statement in the Python programming language is shown below:

while expression:
  while expression:
   statement(s)
  statement(s)

The last thing to note in loop nesting is that you can put any type of loop inside any other type of loop. For example, a while loop can be placed inside a for loop and vice versa.
(for) instance

The following program uses a nested loop to find all prime numbers from 2 to 100:

#!/usr/bin/python

i = 2
while(i < 100):
  j = 2
  while(j <= (i/j)):
   if not(i%j): break
   j = j + 1
  if (j > i/j) : print i, " is prime"
  i = i + 1

print "Good bye!"

When the above code is executed, it produces the following result:

2 is prime
3 is prime
5 is prime
7 is prime
11 is prime
13 is prime
17 is prime
19 is prime
23 is prime
29 is prime
31 is prime
37 is prime
41 is prime
43 is prime
47 is prime
53 is prime
59 is prime
61 is prime
67 is prime
71 is prime
73 is prime
79 is prime
83 is prime
89 is prime
97 is prime
Good bye!