









Python Conditional Statements
What are Conditional Statements?
In real life, we make decisions all the time:
- If it’s raining, take an umbrella.
- If you're hungry, eat something.
- Otherwise, continue your day.
Python also lets us make decisions in our code using conditional statements.
In Python, for conditional statements, we use:
- if – is used check a condition
- elif – is used to check another condition if the first one was false
- else – is used to do specific operations if nothing above is true
1. if Statement
The if
statement is used to run a block of code only when a given condition is True
.
Syntax
if condition:
# code to run if condition is True
if
: The keyword that starts the conditional statement.condition
: An expression that evaluates to eitherTrue
orFalse
.- The colon
:
marks the start of the indented code block. - Indented block: Code that will execute only if the condition is true.
Example
x = 10
if x > 5:
print("x is greater than 5")
x is greater than 5
The variable x
holds the value 10
. When Python checks the condition x > 5
, it evaluates to True
. As a result, the print()
statement inside the if
block is executed, and the message is shown in the output.
Flowchart
2. if-else
Statement
The if-else
statement allows you to define an alternate block of code to run when the condition is False
. It provides a clear choice between two paths.
Syntax
if condition:
# code to run if condition is True
else:
# code to run if condition is False
Syntax Explanation
if
: Starts the conditional check.condition
: An expression that returnsTrue
orFalse
.:
: A colon follows the condition and begins the indented block.- Indented block (under
if
): Executes if the condition isTrue
. else:
: Specifies the alternate block to run if the condition isFalse
.- Indented block (under
else
): Executes if the condition isFalse
.
Example
age = 16
if age >= 18:
print("You can vote.")
else:
print("You cannot vote.")
You cannot vote.
Explanation: The variable age
is assigned the value 16
. Python checks the condition age >= 18
, which evaluates to False
. Therefore, the code inside the else
block runs and prints You cannot vote.
.
3. if-elif-else
Ladder
Use the if-elif-else
structure when you want to test multiple conditions in sequence. Python evaluates each condition in order and executes the block under the first True
condition.
Syntax
if condition1:
# code block 1
elif condition2:
# code block 2
elif condition3:
# code block 3
else:
# default code block if none above are true
Syntax Explanation
if
: Checks the first condition. If it’sTrue
, its block is executed and the rest are skipped.elif
: Stands for “else if.” It lets you check more conditions if the previous ones areFalse
.else
: A fallback that runs if none of theif
orelif
conditions are true.- Only the first block with a
True
condition runs; the rest are ignored.
Example
marks = 75
if marks >= 90:
print("Grade: A")
elif marks >= 70:
print("Grade: B")
elif marks >= 50:
print("Grade: C")
else:
print("Grade: F")
Grade: B
Explanation: The value of marks
is 75
. The first condition (marks >= 90
) is false, so Python checks the next one: marks >= 70
. This is true, so it prints Grade: B
. The rest of the conditions are skipped.
4. Nested if Statements
You can also put one if
inside another. This is called nesting.
num = 10
if num > 0:
if num % 2 == 0:
print("Positive even number")
Positive even number
Why? First, num > 0
is true. Then, 10 % 2 == 0
(means even), so the inner print runs.
Important Notes When Using Conditional Statements
- Use colons (
:
) afterif
,elif
, andelse
. - Indent the code block under each condition using spaces (usually 4).
- Conditions are usually comparisons:
==
,!=
,>
,<
,>=
,<=
.