This document discusses decision making and loops in Python. It begins with an introduction to decision making using if/else statements and examples of checking conditions. It then covers different types of loops - for, while, and do-while loops. The for loop is used when the number of iterations is known, while the while loop is used when it is unknown. It provides examples of using range() with for loops and examples of while loops.

1. Akhil Kaushik
Asstt. Prof., CE Deptt.,
TIT Bhiwani
Decision Making & Loops

2. Decision Making
Decision making is required
when we want to execute a
code only if a certain condition
is satisfied.
if (condition):
statement(s)
else:
statement(s)

3. Decision Making
• Indentation: Python relies on indentation
(whitespace at the beginning of a line) to define
scope in the code.
• Other programming languages often use curly-
brackets for this purpose.
• ‘If’ statement, without indentation (will raise an
error) and so do ‘else’.

4. Decision Making
To simply enter 2
nos. and check if a
> b & vice versa
using ‘if’ statement.

5. Decision Making
• Similar program, but more efficient

6. Decision Making
• Similar program, but most efficient

7. Decision Making
• Short Hand If:
if a > b: print("a is greater than b")
• Short Hand If ... Else:
a = 2
b = 330
print("A") if a > b else print("B")
Not all compilers
accept this style

8. Decision Making
Simple program to check value of a no.

9. Decision Making: Leap Year Check

10. Decision Making: Check Greater No.

11. Loops

12. Loops
• There are the following advantages of loops in
Python.
– It provides code re-usability.
– Using loops, we do not need to write the same code again
and again.
– Using loops, we can traverse over the elements of data
structures (array or linked lists).

13. Loops
for loop
• The for loop is used in the case where we need to execute some part
of the code until the given condition is satisfied.
• The for loop is also called as a pre-tested loop.
• It is better to use for loop if the number of iteration is known in
advance.
while loop
• The while loop is to be used in the scenario where we don't know the
number of iterations in advance.
• The block of statements is executed in the while loop until the
condition specified in the while loop is satisfied.
• It is also called a pre-tested loop.
do-while loop
• The do-while loop continues until a given condition satisfies.
• It is also called post-tested loop.
• It is used when it is necessary to execute the loop at least once
(mostly menu driven programs).

14. For Loop

15. For Loop
• The range() function: It is used to generate the
sequence of the numbers.
• If we pass the range(10), it will generate the
numbers from 0 to 9.
• The syntax of the range() function is given below:
range(start, stop, step size)

16. For Loop

17. For Loop

18. For Loop

19. While Loop

20. While Loop

21. Akhil Kaushik
akhilkaushik05@gmail.com
9416910303
CONTACT ME AT:
Akhil Kaushik
akhilkaushik05@gmail.com
9416910303
THANK YOU !!!