Python For Loops

Python For loop is used for sequential traversal i.e.it is used for iterating over an iterable like String, Tuple, List, Set, or Dictionary.

for var in iterable:
# statements              
              

fruits = ["apple", "banana", "orange"]
for fruit in fruits:
    print(fruit)
             
              

Flowchart of For Loop

Here the iterable is a collection of objects like lists, and tuples.
The indented statements inside the for loops are executed once for each item in an iterable.
The variable var takes the value of the next item of the iterable each time through the loop.

for x in 'Python':
print(x)

Output

    p
    y
    t
    h
    o
    n

              

Looping Through a String

Even strings are iterable objects, they contain a sequence of characters:

# Define a string
my_string = "Hello, CodeLines!"

# Loop through each character in the string
for char in my_string:
    print(char)


Output

H
e
l
l
o
,
 
C
o
d
e
L
i
n
e
s
!


              

The break Statement

With the break statement we can stop the loop before it has looped through all the items:

fruits = ["apple", "banana", "cherry"]
for x in fruits:
  if x == "banana":
    break
  print(x)
              

The continue Statement

fruits = ["apple", "banana", "cherry"]
for x in fruits:
  if x == "banana":
    continue
  print(x) 

 
   
  print(x)
              

Else in For Loop

The else keyword in a for loop specifies a block of code to be executed when the loop is finished:

for x in range(6):
print(x)
  
    else:
  print("Finally finished!") 

 
              

Nested Loops

A nested loop is a loop inside a loop.

adj = ["red", "big", "tasty"]
fruits = ["apple", "banana", "cherry"]
for x in adj:
  for y in fruits:
   
  print(x, y)

              

The pass Statement

for loops cannot be empty, but if you for some reason have a for loop with no content, put in the passement to avoid getting an error.

for x in[0, 1, 2]:
  pass