#10 - For Loop

A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string). This is less like the for keyword in other programming languages, and works more like an iterator method as found in other object-orientated programming languages. With the for loop we can execute a set of statements, once for each item in a list, tuple, set etc.

EXAMPLE:

  1. fruits = ["apple", "banana" , "cherry"]
  2. for x in fruits:
  3.   print(x)


OUTPUT :

apple
banana
cherry
The for loop does not require an indexing variable to set beforehand like we have in while loops

range() :


To loop through a set of code a specified number of times, we can use the range() function, The range() function returns a sequence of numbers, starting from 0 by default, and increments by 1 (by default), and ends at a specified number.

EXAMPLE:

for x in range(6):
  print(x)


OUTPUT:

1
2
3
4
5
Note that range(6) is not the values of 0 to 6, but the values 0 to 5.

The range() function defaults to 0 as a starting value. However it is possible to specify the starting value by adding a parameter: range(2, 6), which means values from 2 to 6 (but not including 6):

EXAMPLE:

Using the start parameter:
for x in range(2, 6):
  print(x)


OUTPUT:

2
3
4
5


The range() function defaults to increment the sequence by 1, however it is possible to specify the increment value by adding a third parameter: range(2, 30, 3):

EXAMPLE:

Increment the sequence with 3 (default is 1):
for x in range(2, 30, 3):
  print(x)


OUTPUT:

2
5
8
11
15
18
21
24
27