Introduction to Python

Course Content

Introduction to Python

Introduction to Python

1. First Acquaintance with Python

The Very First Steps in Python How to Use Comments for Readability Perform Simple Math in Python Handle More Challenging Math in Python Bringing Python Fundamentals Together

2. Variables and Types in Python

How to Store Numbers in Python Python Naming Rules for Variables How to Work with Variables in Python Data Types in Python Challenge: Converting Kilometers to Miles Store Text with Strings in Python String Indexing in Python Negative Indexing and String Length in Python String Slicing in Python Challenge: Retrieving Letters from String String Concatenation in Python

3. Conditional Statements in Python

Boolean Data Type in Python Challenge: Working with Comparison Operators How to Combine Conditions in Python Challenge: Working with Logical Operators Membership Operators and Type Comparisons in Python How to Use if/else Expressions in Python Challenge: Running a Grocery Store Challenge: Creating Odd and Even Logic if/elif/else Expressions Challenge: Running Grocery Store Extended Challenge: Outputting Positive, Negative or Zero

4. Other Data Types in Python

Python Lists Common List Methods in Python Challenge: Updating List Nested Lists in Python Challenge: Retrieving Information from Nested List Python Tuples Common Tuple Methods in Python Challenge: Updating Tuple Nested Tuples in Python Challenge: Retrieving Information from Nested Tuple Python Dictionaries Challenge: Completing Dictionary Common Dictionary Methods in Python Challenge: Updating Dictionary

5. Loops in Python

Explore the While Loop in Python Challenge: Working with the While Loop Explore the For Loop in Python Challenge: Working with the For Loop Range Function in Python Challenge: Using the Range Function How to Iterate Over Indexes in Python Explore Nested Loops in Python

6. Functions in Python

Built-in Functions in Python Challenge: Converting Heights How to Create Functions in Pythons Challenge: Writing First Function Use of if/else Statements in Python Functions Challenge: Identifying Positive Values Functions Without Return in Python Challenge: Creating Logging Function Modifying Functions in Python Challenge: Updating Logic of the Function Lambda Functions in Python Challenge: Creating Lambda Function

How to Use if/else Expressions in Python

Now that we're acquainted with conditional operators and know how to use them, we can branch our code based on certain conditions. In Python, this is achieved with the following structure:

In the example above, the condition can be either a conditional statement or a boolean value. For example, it might look like a != 4 or b > 100. The commands beneath if and else are instructions to be executed depending on whether the condition is met. These could be print() functions, variable assignments, arithmetic operations, string manipulations, and more.

Let's walk through an example: Suppose you have a string and you want to determine if it's long. We'll define a string as 'long' if it contains more than 20 characters.


              1234567891011121314151617
            
# Assign some variable
test = "small string"

# Conditional statement
if len(test) > 20:
    print("This string is long!")
else:
    print("Nothing special")
    
# Check on different string
test = "This string is very-very and very large"

# Conditional statement
if len(test) > 20:
    print("This string is long!")
else:
    print("Nothing special")

Note

Remember, the code blocks under the if and else statements should have consistent indentation (e.g., 2 spaces, 4 spaces, etc.).

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Section 3. Chapter 6

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