Python Conditional Statements
Table Of Contents
- What Is Python Conditional Statement?
- Types Of Conditional Statement.
- if statements
- if-else statements
- if-elif ladder
- Nested statements
(1) What Is Python Conditional Statements?
- When our program executes, it will run line by line.
Suppose, you want to execute some set of codes based on some condition, you can use control flow statements.
- Decision-making statements in programming languages decide the direction of the flow of program execution.
- In the above picture, you can see that if there is water on the road, you will not walk on that path.
- So in python, you can also implement this logic by using conditional statements.
(2) Types Of Conditional Statements?
- if Statements.
- if-else Statements.
- if-elif Statements.
- Nested Statements.
(3) If Statement
- Python if Statement is used for decision-making operations.
- It contains a body of code that runs only when the condition given in the if statement is true.
- If the condition is false, then the optional else statement runs .
Python If Statement Syntax:
if Condition:
Body Of If BlockExample-1
mark = 60
if mark >= 60:
print("Pass")Output:
PassExample-2
company = "Nokia"
price = 10000
if company=="Nokia" and price <= 10000:
print('Buy')Output:
Buy(4) If-else Statement
- Suppose you have two possible options to execute, if the first option is not satisfying then you need to run the second option.
- In that case, you can use an if-else statement.
Python If Statement Syntax:
if Condition:
Body Of If Block
else:
Body Of If BlockExample-1
number = 10
if number % 2 == 0:
print("Even Number")
else:
print("Odd Number")Output:
Even NumberExample-2
grade = 'A'
experience = 5
if grade == 'A' and experience>=5:
print('Eligable')
else:
print('Not Eligable')Output:
Eligable(5) If-elif Statement
- When you have more than two conditions to check, then you can use if-elif statement.
- It allows us to implement multiple conditions in our programming.
Python If Statement Syntax:
if Condition:
Body Of If Block
elif Condition:
Body Of elif Block
elif Condition:
Body Of elif Block
......
else:
Body Of else BlockExample-1
num = -10
if num > 0:
print("Positive number")
elif num == 0:
print("Zero")
else:
print("Negative number")Output:
Negative NumberExample-2
country = 'India'
if country == 'India':
print('Democratic Country')
elif country == 'China':
print('Non Democratic Country')
elif country == 'USA':
print('Democratic Country')
else:
print('Not In The List')Output:
Democratic Country(6) Nested If Statement
- A Nested IF statement is one in which an If statement is implemented inside another If statement.
- This is used when a variable must be processed more than once.
- If, If-else, and If…elif…else statements can be used in the program.
In Nested If statements, the indentation (whitespace at the beginning) to determine the scope of each statement should take precedence.
Python Nested If Statement Syntax:
if (condition 1):
#Executes if condition 1 is true
if (condition 2):
#Executes if condition 2 is true
#Condition 2 ends here
#Condition 1 ends here
elif (condition 3):
#Execute this if condition 3 is true
if (condition 4):
#Execute this if condition 4 is true
if (condition 5):
#Execute this if condition 5 is true
else:
#Execute this block if non of the condition satisfyExample-1
num = 8
if num >= 0:
if num == 0:
print("zero")
else:
print("Positive number")
else:
print("Negative number")Output:
Positive NumberExample-2
price=100
quantity=10
amount = price*quantity
if amount > 200:
if amount >1000:
print("The amount is greater than 1000")
else:
if amount 800:
print("The amount is between 800 and 1000")
elif amount 600:
print("The amount is between 600 and 1000")
else:
print("The amount is between 400 and 1000")
elif amount == 200:
print("Amount is 200")
else:
print("Amount is less than 200")Output:
“The amount is between 400 and 1000.”