Python If...Else

Python is an interpreted, high-level, general-purpose programming language that is widely used by programmers worldwide. It is known for its simplicity and readability, making it an excellent choice for beginners and experienced programmers alike. One of the most fundamental aspects of programming in Python is the use of conditions.

Introduction to Python Conditions

Conditions in Python are used to make decisions based on whether a particular condition is true or false. The most common type of condition is the "if" statement. This statement evaluates whether a particular expression is true or false and executes a block of code if the expression is true.

The syntax of the "if" statement in Python is as follows:

if expression:
    # code to be executed if the expression is true

Let's look at an example. Suppose we have a variable x that contains the value 5, and we want to check if x is greater than 3. We can use the "if" statement as follows:

x = 5
if x > 3:
    print("x is greater than 3")

This code will output "x is greater than 3" because the expression x > 3 is true.

Python Comparison Operators

In Python, comparison operators are used to compare two values. The result of the comparison is a boolean value, either True or False. Here are the comparison operators in Python:

• > greater than
• < less than
• >= greater than or equal to
• <= less than or equal to
• == equal to
• != not equal to

We can use these comparison operators in our "if" statements to make decisions based on the values of variables.

Python Logical Operators

Python also has three logical operators: "and", "or", and "not". These operators are used to combine multiple conditions to make more complex decisions.

The "and" operator returns True if both conditions are True, and False otherwise. The "or" operator returns True if either condition is True, and False otherwise. The "not" operator returns the opposite boolean value of the condition.

Here's an example of how to use logical operators in Python:

x = 5
y = 10
if x > 3 and y < 20:
    print("Both conditions are true")

This code will output "Both conditions are true" because both conditions in the "if" statement are true.

Python If-Else Statements

Sometimes we want to execute a block of code if the condition is true, and a different block of code if the condition is false. We can use the "if-else" statement to accomplish this.

The syntax of the "if-else" statement is as follows:

if expression:
    # code to be executed if the expression is true
else:
    # code to be executed if the expression is false

Let's look at an example. Suppose we have a variable x that contains the value 2, and we want to check if x is greater than 3. We can use the "if-else" statement as follows:

x = 2
if x > 3:
    print("x is greater than 3")
else:
    print("x is less than or equal to 3")

This code will output "x is less than or equal to 3" because the expression x > 3 is false

Python If-Elif-Else Statements

Sometimes we want to check multiple conditions and execute different blocks of code based on the conditions. We can use the "if-elif-else" statement to accomplish this.

The syntax of the "if-elif-else" statement is as follows:

if expression1:
    # code to be executed if expression1 is true
elif expression2:
    # code to be executed if expression2 is true and expression1 is false
else:
    # code to be executed if both expression1 and expression2 are false

Let's look at an example. Suppose we have a variable x that contains the value 2, and we want to check if x is greater than 3, equal to 3, or less than 3. We can use the "if-elif-else" statement as follows:

x = 2
if x > 3:
    print("x is greater than 3")
elif x == 3:
    print("x is equal to 3")
else:
    print("x is less than 3")

This code will output "x is less than 3" because the expression x > 3 is false and the expression x == 3 is also false.

Conclusion

In conclusion, conditions are an essential aspect of programming in Python. They allow us to make decisions based on the values of variables and execute different blocks of code based on those decisions. By understanding Python conditions, you will be able to write more complex and powerful programs.

We hope this article has been helpful in explaining Python conditions. If you have any questions or comments, please feel free to leave them below.

Thank you for reading, and happy programming!