For loop of Python

The for loop in python has the ability to iterate over the items of any sequence, such as a list or a string.

The syntax of the loop look is:

for iterating_var in sequence:

statements(s)

if a sequence contains an expression list, it is evaluated first. Then, the first item in the sequence is assigned to the iterating variable iterating_var. Next, the statements block is executed. Each item in the list is assigned to iterating_var, and the statements(s) block is executed until the entire sequence is exhausted.

Note: in python, all the statements indented by the same number of character spaces after a programming construct are considered to be part of a single block of code. Python uses indentation as its method of grouping statements.

Example:

#!/usr/bin/python

for letter in‘python’ : #First Example

print ‘Curre t Letter : ’, letter

fruits = [‘banana’, ‘apple’, ‘mango’]

for fruit in fruits: #Second Example

print ‘Current fruit :’, fruit

print “Good bye!”

This will produce following result:

Current Letter : P

Current Letter : y

Current Letter : t

Current Letter : h

Current Letter : o

Current Letter : n

Current fruit : banana

Current fruit : apple

Current fruit : mango

Good bye!

Iterating by sequence index:

An alternative way of iterating through each item is by index offset into the sequence itself:

Example:

#!/usr/bin/python

fruits = [‘banana’, ‘apple’, ‘mango’]

for index in range (len(fruits)):

print ‘Current fruit :’, fruits[index]

print “Good bye!”

This will produce following result:

Current fruit : banana

Current fruit : apple

Current fruit : mango

Good bye!