Course Content

Introduction to Python Video Course

1. Getting Started

First Steps Comments Simple Math Operations Grocery Calculation Capstone Recap

2. Variables and Types

Data Types Storing Data in Variables Variable Naming Rules Using Variables String Indexing and Length String Slicing and Concatenation Inventory Sorting Capstone Challenge Recap

3. Conditional Statements

Boolean Data Type Combining Conditions Challenge Membership Operators and Type Comparisons Conditional Expressions Capstone Challenge Recap

4. Other Data Types

Lists and List Methods Nested Lists Challenge Tuples and Tuple Methods Tuple Operations Challenge Dictionaries and Dictionary Methods Capstone Challenge Recap

5. Loops

For Loops While Loops Range Function Iterating Over Indexes Challenge Nested Loops Capstone Challenge Challenge Recap

6. Functions

Built-in Functions User Defined Functions Challenge Functions with no `return`Modifying Functions Capstone Challenge Recap

User Defined Functions

A user-defined function is a block of code that you create to perform a specific task. Unlike built-in functions, which are provided by Python, user-defined functions are written by you to solve specific problems in your programs. Once defined, these functions can be reused multiple times, making your code more organized, efficient, and easier to maintain.

Now, let's watch as Alex demonstrates how to create and use user-defined functions to simplify tasks:

Syntax: The basic structure of a user-defined function in Python looks like this:

def: This keyword is used to start the definition of a function;
function_name: This is the name you give to your function. It should be descriptive of what the function does, making your code more readable;
parameters: These are variables that you pass into the function. They act as placeholders for the values that you’ll provide when calling the function. A function can have zero or more parameters;
The colon : signifies the start of the function’s code block;
Code block: This is the body of the function, where you write the code that the function will execute. It must be indented;
return: This statement is used to exit the function and return a result. Not all functions need a return statement, but it’s useful when you want to send a value back to where the function was called;

Parameters and Arguments

Parameters: Parameters are the variables listed inside the parentheses in the function definition. They are used to receive values (arguments) that are passed into the function:


              123
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

Arguments: Arguments are the actual values you provide to the function when you call it. These values are assigned to the function’s parameters.


              1
            
greet_customer("Alice")

In this example, "Alice" is the argument received by the name parameter in the greet_customer function.


              12345
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

greet_customer("Alice")

Void Functions

Not all functions need to return a value. Some functions perform a task but don’t send anything back to the caller. These are called void functions. In Python, a void function is a user-defined function that doesn’t include a return statement or where the return statement doesn’t return any value (i.e., it returns None).

In this example, greet_customer is a void function because it performs the action of printing a greeting but doesn’t return any result that can be stored or used elsewhere in your program:


              1234
            
def greet_customer(name):
    print(f"Hello, {name}! Welcome to our store.")

greet_customer("Alice")

Example Application

User-defined functions can be used to encapsulate repetitive tasks, making your code cleaner and more modular. For instance, if you frequently need to calculate discounts for various products in your store, you can create a function to handle the discount calculation, which you can then reuse whenever needed.


              12345678910
            
# price and discount are the parameters of the function
def apply_discount(price, discount):
    discounted_price = price * (1 - discount)
    return discounted_price

# Call the apply_discount function and pass in price and discount as arguments
price = 100
discount = 0.2
final_price = apply_discount(price, discount)
print(f"The final price is ${final_price}")

Task

In this challenge, you will create a simple function to help manage inventory levels in a grocery store. The goal is to calculate the quantity of products that need to be ordered to reach a desired stock level.

Task:

Define a Function: Use the proper keyword to start the definition of a function and then name the function restock_quantity.
Return a Result: Use the proper keyword to return the value of restock_quantity.
Call the Function with Arguments: Call the restock_quanty function with current_stock and desired_stock as arguments. We will store the results in a variable named restock_needed.

Task

Task:

Define a Function: Use the proper keyword to start the definition of a function and then name the function restock_quantity.
Return a Result: Use the proper keyword to return the value of restock_quantity.
Call the Function with Arguments: Call the restock_quanty function with current_stock and desired_stock as arguments. We will store the results in a variable named restock_needed.

index

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Section 6. Chapter 2

User Defined Functions

Now, let's watch as Alex demonstrates how to create and use user-defined functions to simplify tasks:

Syntax: The basic structure of a user-defined function in Python looks like this:

def: This keyword is used to start the definition of a function;
function_name: This is the name you give to your function. It should be descriptive of what the function does, making your code more readable;
parameters: These are variables that you pass into the function. They act as placeholders for the values that you’ll provide when calling the function. A function can have zero or more parameters;
The colon : signifies the start of the function’s code block;
Code block: This is the body of the function, where you write the code that the function will execute. It must be indented;
return: This statement is used to exit the function and return a result. Not all functions need a return statement, but it’s useful when you want to send a value back to where the function was called;

Parameters and Arguments

Parameters: Parameters are the variables listed inside the parentheses in the function definition. They are used to receive values (arguments) that are passed into the function:


              123
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

Arguments: Arguments are the actual values you provide to the function when you call it. These values are assigned to the function’s parameters.


              1
            
greet_customer("Alice")

In this example, "Alice" is the argument received by the name parameter in the greet_customer function.


              12345
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

greet_customer("Alice")

Void Functions

In this example, greet_customer is a void function because it performs the action of printing a greeting but doesn’t return any result that can be stored or used elsewhere in your program:


              1234
            
def greet_customer(name):
    print(f"Hello, {name}! Welcome to our store.")

greet_customer("Alice")

Example Application


              12345678910
            
# price and discount are the parameters of the function
def apply_discount(price, discount):
    discounted_price = price * (1 - discount)
    return discounted_price

# Call the apply_discount function and pass in price and discount as arguments
price = 100
discount = 0.2
final_price = apply_discount(price, discount)
print(f"The final price is ${final_price}")

Task

Task:

Define a Function: Use the proper keyword to start the definition of a function and then name the function restock_quantity.
Return a Result: Use the proper keyword to return the value of restock_quantity.
Call the Function with Arguments: Call the restock_quanty function with current_stock and desired_stock as arguments. We will store the results in a variable named restock_needed.

Task

Task:

Define a Function: Use the proper keyword to start the definition of a function and then name the function restock_quantity.
Return a Result: Use the proper keyword to return the value of restock_quantity.
Call the Function with Arguments: Call the restock_quanty function with current_stock and desired_stock as arguments. We will store the results in a variable named restock_needed.

index

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Section 6. Chapter 2

User Defined Functions

Now, let's watch as Alex demonstrates how to create and use user-defined functions to simplify tasks:

Syntax: The basic structure of a user-defined function in Python looks like this:

def: This keyword is used to start the definition of a function;
function_name: This is the name you give to your function. It should be descriptive of what the function does, making your code more readable;
parameters: These are variables that you pass into the function. They act as placeholders for the values that you’ll provide when calling the function. A function can have zero or more parameters;
The colon : signifies the start of the function’s code block;
Code block: This is the body of the function, where you write the code that the function will execute. It must be indented;
return: This statement is used to exit the function and return a result. Not all functions need a return statement, but it’s useful when you want to send a value back to where the function was called;

Parameters and Arguments

Parameters: Parameters are the variables listed inside the parentheses in the function definition. They are used to receive values (arguments) that are passed into the function:


              123
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

Arguments: Arguments are the actual values you provide to the function when you call it. These values are assigned to the function’s parameters.


              1
            
greet_customer("Alice")

In this example, "Alice" is the argument received by the name parameter in the greet_customer function.


              12345
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

greet_customer("Alice")

Void Functions

In this example, greet_customer is a void function because it performs the action of printing a greeting but doesn’t return any result that can be stored or used elsewhere in your program:


              1234
            
def greet_customer(name):
    print(f"Hello, {name}! Welcome to our store.")

greet_customer("Alice")

Example Application


              12345678910
            
# price and discount are the parameters of the function
def apply_discount(price, discount):
    discounted_price = price * (1 - discount)
    return discounted_price

# Call the apply_discount function and pass in price and discount as arguments
price = 100
discount = 0.2
final_price = apply_discount(price, discount)
print(f"The final price is ${final_price}")

Task

Task:

Define a Function: Use the proper keyword to start the definition of a function and then name the function restock_quantity.
Return a Result: Use the proper keyword to return the value of restock_quantity.
Call the Function with Arguments: Call the restock_quanty function with current_stock and desired_stock as arguments. We will store the results in a variable named restock_needed.

Task

Task:

Define a Function: Use the proper keyword to start the definition of a function and then name the function restock_quantity.
Return a Result: Use the proper keyword to return the value of restock_quantity.
Call the Function with Arguments: Call the restock_quanty function with current_stock and desired_stock as arguments. We will store the results in a variable named restock_needed.

index

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Now, let's watch as Alex demonstrates how to create and use user-defined functions to simplify tasks:

Syntax: The basic structure of a user-defined function in Python looks like this:

def: This keyword is used to start the definition of a function;
function_name: This is the name you give to your function. It should be descriptive of what the function does, making your code more readable;
parameters: These are variables that you pass into the function. They act as placeholders for the values that you’ll provide when calling the function. A function can have zero or more parameters;
The colon : signifies the start of the function’s code block;
Code block: This is the body of the function, where you write the code that the function will execute. It must be indented;
return: This statement is used to exit the function and return a result. Not all functions need a return statement, but it’s useful when you want to send a value back to where the function was called;

Parameters and Arguments

Parameters: Parameters are the variables listed inside the parentheses in the function definition. They are used to receive values (arguments) that are passed into the function:


              123
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

Arguments: Arguments are the actual values you provide to the function when you call it. These values are assigned to the function’s parameters.


              1
            
greet_customer("Alice")

In this example, "Alice" is the argument received by the name parameter in the greet_customer function.


              12345
            
def greet_customer(name):
    greeting = print(f"Hello, {name}! Welcome to our store.")
    return greeting

greet_customer("Alice")

Void Functions

In this example, greet_customer is a void function because it performs the action of printing a greeting but doesn’t return any result that can be stored or used elsewhere in your program:


              1234
            
def greet_customer(name):
    print(f"Hello, {name}! Welcome to our store.")

greet_customer("Alice")

Example Application


              12345678910
            
# price and discount are the parameters of the function
def apply_discount(price, discount):
    discounted_price = price * (1 - discount)
    return discounted_price

# Call the apply_discount function and pass in price and discount as arguments
price = 100
discount = 0.2
final_price = apply_discount(price, discount)
print(f"The final price is ${final_price}")

Task

Task:

Define a Function: Use the proper keyword to start the definition of a function and then name the function restock_quantity.
Return a Result: Use the proper keyword to return the value of restock_quantity.
Call the Function with Arguments: Call the restock_quanty function with current_stock and desired_stock as arguments. We will store the results in a variable named restock_needed.

index

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Section 6. Chapter 2

Switch to desktop for real-world practiceContinue from where you are using one of the options below