Lesson 8 of 30
In Progress

Conditional Statements (if, elif, else)

Yasin Cakal

In Python, conditional statements are a way to control the flow of your program based on certain conditions. They allow you to execute different pieces of code depending on whether a condition is true or false. In this article, we will learn about the three main types of conditional statements in Python: “if”, “elif”, and “else”.

The “if” Statement

The “if” statement is the most basic type of conditional statement in Python. It allows you to execute a block of code if a condition is true. The syntax for an “if” statement is as follows:

if condition:
# code to be executed if condition is true


For example, consider the following code:

x = 10
if x > 5:
print("x is greater than 5")


The output of this code will be “x is greater than 5”.

You can also include an “else” clause in an “if” statement to specify a block of code to be executed if the condition is false. The syntax for an “if” statement with an “else” clause is as follows:

if condition:
# code to be executed if condition is true
else:
# code to be executed if condition is false


For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
else:
print("x is not greater than 15")


The output of this code will be “x is not greater than 15”.

The “elif” Statement

The “elif” statement is an abbreviation of “else if”, and it allows you to specify multiple conditions in an “if” statement. The syntax for an “elif” statement is as follows:

if condition1:
# code to be executed if condition1 is true
elif condition2:
# code to be executed if condition1 is false and condition2 is true


For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
elif x > 5:
print("x is greater than 5 but not greater than 15")


The output of this code will be “x is greater than 5 but not greater than 15”.

You can include multiple “elif” clauses in an “if” statement to specify multiple conditions. The code for the first condition that is true will be executed, and the rest of the conditions will be skipped.

For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
elif x > 5:
print("x is greater than 5 but not greater than 15")
elif x > 0:
print("x is greater than 0 but not greater than 5")


The output of this code will be “x is greater than 5 but not greater than 15”.

The “else” Statement

You can also include an “else” clause at the end of an “if” statement with “elif” clauses to specify a block of code to be executed if none of the conditions are true. The syntax for an “if” statement with “elif” clauses and an “else” clause is as follows:

if condition1:
# code to be executed if condition1 is true
elif condition2:
# code to be executed if condition1 is false and condition2 is true
...
else:
# code to be executed if all conditions are false

For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
elif x > 5:
print("x is greater than 5 but not greater than 15")
elif x > 0:
print("x is greater than 0 but not greater than 5")
else:
print("x is not greater than 0")


The output of this code will be “x is greater than 5 but not greater than 15”.

Conclusion

In this article, we learned about the three main types of conditional statements in Python: “if”, “elif”, and “else”. We saw how to use these statements to control the flow of our program based on certain conditions. Understanding how to use these statements is an essential skill for any Python programmer.

In our “Introduction to Python” course, we will cover these concepts in more depth and show you how to use them to solve real-world problems. We hope you will join us on this journey!

Exercises

Here are some exercises with solutions to help you practice what you just learned:

How do you use an “if” statement in Python?

To use an “if” statement in Python, you can specify a condition after the “if” keyword and a block of code to be executed if the condition is true. The syntax for an “if” statement is as follows:

if condition:
# code to be executed if condition is true


For example, consider the following code:

x = 10
if x > 5:
print("x is greater than 5")


The output of this code will be “x is greater than 5”.

How do you use an “else” clause in an “if” statement in Python?

To use an “else” clause in an “if” statement in Python, you can specify the “else” keyword after the “if” clause and a block of code to be executed if the condition is false. The syntax for an “if” statement with an “else” clause is as follows:

if condition:
# code to be executed if condition is true
else:
# code to be executed if condition is false


For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
else:
print("x is not greater than 15")


The output of this code will be “x is not greater than 15”.

How do you use an “elif” clause in an “if” statement in Python?

To use an “elif” clause in an “if” statement in Python, you can specify the “elif” keyword after the “if” clause and a condition, and a block of code to be executed if the condition is true. The syntax for an “elif” clause is as follows:

if condition1:
# code to be executed if condition1 is true
elif condition2:
# code to be executed if condition1 is false and condition2 is true


For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
elif x > 5:
print("x is greater than 5 but not greater than 15")


The output of this code will be “x is greater than 5 but not greater than 15”.

How do you use an “else” clause at the end of an “if” statement with “elif” clauses in Python?

To use an “else” clause at the end of an “if” statement with “elif” clauses in Python, you can specify the “else” keyword after the last “elif” clause and a block of code to be executed if none of the conditions are true. The syntax for an “if” statement with “elif” clauses and an “else” clause is as follows:

if condition1:
# code to be executed if condition1 is true
elif condition2:
# code to be executed if condition1 is false and condition2 is true
...
else:
# code to be executed if all conditions are false


For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
elif x > 5:
print("x is greater than 5 but not greater than 15")
elif x > 0:
print("x is greater than 0 but not greater than 5")
else:
print("x is not greater than 0")


The output of this code will be “x is greater than 5 but not greater than 15”.

How do you use multiple “elif” clauses in an “if” statement in Python?

To use multiple “elif” clauses in an “if” statement in Python, you can specify multiple “elif” clauses after the “if” clause, each with a different condition and a block of code to be executed if the condition is true. The code for the first condition that is true will be executed, and the rest of the conditions will be skipped.

The syntax for an “if” statement with multiple “elif” clauses is as follows:

if condition1:
# code to be executed if condition1 is true
elif condition2:
# code to be executed if condition1 is false and condition2 is true
...
elif conditionN:
# code to be executed if all previous conditions are false and conditionN is true


For example, consider the following code:

x = 10
if x > 15:
print("x is greater than 15")
elif x > 5:
print("x is greater than 5 but not greater than 15")
elif x > 0:
print("x is greater than 0 but not greater than 5")
elif x > -5:
print("x is greater than -5 but not greater than 0")


The output of this code will be “x is greater than 5 but not greater than 15”.