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Loop
Statements

Loops In Python

The loops in python it allows a you to execute multiple statement or block of code repeatly. the loop is also known as a iteration . means repetitive structure. when you want to print hello in 1000 times but we con't write 1000 times print statement that's why we using loops to execute a block of code in multiple times.

The python provides mainly two types of loops

  1. For Loop
  2. While Loop

Let understand by loops

While Loop

The while loop is a indefinite loop which means the code is execute or iterate as long as condition is true. and the while loop contain conditions to exit the loop or terminate the loop but for loop exit using range() function. when we does not assign the condition it will repeat the process does not end . the while loop evaluate the condition first then execute the body of the loop or statements . if condition is false then the loop was exit

Syntax

while condition:
      statement

FlowChart

Block of Statements Exit Start No Yes Condition

Examples

i=0
while i<=10:
          print(i)
i=i+1

Output

0
1
2
3
4
5
6
7
8
9
10

infinite

i=0
while i<10:
           print('Hello')# The loop does not end because the i does not increment

Output

Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
Hello
.........# does not end

For Loop

The for loop in python it is a Definite loop which means it execute the statements repeatly until the last item reached. This is also used if we have a list of thing to loop through, like sequences that is list, tuple, dict and String . all examples in the below

Here , val accessed each item of sequence on each iteration. loop continues until we reach last item

Syntax

For val in sequence:
           statement

FlowChart

No Yes Body of For Exit Start Last item reached?

Examples


for num in range(1,10,2)
        print(num)

output

1
3
5
7
9

Program

names=["Darshan","Tharun","Hemanth"]
for name in names
      print(name)

output

Darshan
Tharun
Hemanth

Program

tuple=(1,2,3," Darshan ", " Therun", " Hemanth")
for tuples in tuple:
      print(tuples)

Output

1
2
3
Darshan
Therun
Hemanth

Program

Dictionary = {
"name": "Darshan",
"age": 19,
"Place": "Kolar"
}
for key, value in Dictionary.items():
      print(f"{key}: {value}")

Output

name: Darshan
age: 19
Place: Kolar

Nested Loop

The python provides the nested loops which means the python code program has one loop within another loop is called nested loop .Example in the below

Example

for i in range(2, 11):
   for j in range(2, 11):
         print(f"{i * j:4}", end="")
   print()

Output

2 | 4 6 8 10 12 14 16 18 20
3 | 6 9 12 15 18 21 24 27 30
4 | 8 12 16 20 24 28 32 36 40
5 | 10 15 20 25 30 35 40 45 50
6 | 12 18 24 30 36 42 48 54 60
7 | 14 21 28 35 42 49 56 63 70
8 | 16 24 32 40 48 56 64 72 80
9 | 18 27 36 45 54 63 72 81 90
10 | 20 30 40 50 60 70 80 90 100