In this tutorial we are going to learn :

  • For Loops
  • Iterables
  • The range () Function
  • Nested Loops

 

 

 

For Loop

 

We use loops for iterating over a sequence ( string, list, tuple, dictionary, set ) or any
other iterable objects

 

 

Iterables

 

Examples of iterating lists and strings.

  • Iterating a List

 

Example :

Example of iterating a list.

# for loops

my_list = [1, 2, 3, 4, 5]

# iterating a list 
for x in my_list:
    print(x)

 

 
 
Iterating a String

 

Example :

Example of Iterating a String

# for loops

name = "James"

# iterating a string
for x in name:
    print(x)

 

 

 

The range () Function

 

We use the range () function to generate a specified number of loops on a set of code. 

Example : 

for number in range(5):
    print("Hello ")

 

Note :

range () function here is not the values 0 to 5 , values 0 to 4 . In our program
range (5) function will generate numbers 0 to 4.
Let’s Look at the example below. You can see the range() function’s index numbers
too

for number in range(5):
    print("Hello", number)

 

  • range() function defaults to 0 as a starting value. But we can determine the starting value by adding a new parameter. 

 

Example :

You can see that our index numbers generated from 1 to 4.

for number in range(1,5):
    print("Hello", number)
 
  • We can also set the number‘s increment value by adding a new third parameter.

 

Example :

  • Generated from 1 to 10.
  • The increment value is 2.
for number in range(1,10,2):
    print("Hello", number)




Nested Loops


Nested loops are basically a loop inside a loop.

Example :

In this program,

  • the inner loop will be executed one time for each iteration of the outer loop.
for number in range(3):
    for x in range(2):
        print(f"({number}, {x})")