Learn Nested Loops

Nested loops extend the power of simple loops by allowing you to perform repeated actions across multiple dimensions. This is crucial for handling more complex tasks in a grocery store environment, such as organizing multi-layered inventory data or coordinating schedules across different departments.

Watch as Alex showcases how nested loops can be utilized to enhance efficiency and manage complex scenarios in our grocery store setting:

Nested loops are incredibly useful in programming when you need to loop through multiple sequences at the same time. By placing one loop inside another, you can iterate over elements in two or more dimensions, such as a list of lists:


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# List of lists representing stock in different departments
department_stocks = [
    ["Apples", "Bananas", "Cherries"],  # Fruits
    ["Milk", "Cheese", "Butter"],       # Dairy
    ["Bread", "Bagels", "Muffins"]      # Bakery
]

print("Inventory Check:")
for department in department_stocks:
    print(department) # For each iteration of the outer loop, the entire sublist is accessed
    # The inner loop then iterates over the items in that sublist
    for item in department:
        print(f" - {item}")
    print("")  # Add a line break for clarity

Notice how the outer loop iterates through each sublist in department_stocks, where each sublist represents a different department. The inner loop then iterates through all the items within each sublist. The outer loop does not proceed to the next sublist until the inner loop has finished iterating through all items in the current sublist.

Task

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You are given two lists of grocery items:

produce, which contains fruits and vegetables
dairy, which contains dairy products

Your task is to combine these two lists into a single list called groceries, where each original list becomes an element inside groceries.

Then, use nested for loops to print the name of every item:

The outer loop should go through each category (called section) in groceries.
The inner loop should go through each item inside the current section.
Print each item on its own line in the format: Item name: <item>

Solution

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Section 5. Chapter 6

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