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Code：[ZachxPKU/AcceleratedCPlusPlus]
Chapter 3 Introducing Lists
3.1 What is a list?
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles)
3.1.1 Accessing elements in a list
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles[0])
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles[0].title())
3.1.2 Index Positions Start at 0, Not 1
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles[1])
print(bicycles[3])
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles[-1])
3.1.3 Using Individual Values from a List
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
message = f"My first bicycle was a {bicycles[0].title()}."
print(message)
3.2 Changing, Adding, and Removing Elements
3.2.1 Modifying Elements in a List
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
motorcycles[0] = 'ducati'
print(motorcycles)
3.2.2 Adding Elements to a List
Appending elements to the end of a list
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
motorcycles.append('ducati')
print(motorcycles)
motorcycles = []
motorcycles.append('honda')
motorcycles.append('yamaha')
motorcycles.append('suzuki')
print(motorcycles)
Inserting elements into a list
motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.insert(0, 'ducati')
print(motorcycles)
3.2.3 Removing elements from a list
Removing an item using the del statement
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
del motorcycles[0]
print(motorcycles)
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
del motorcycles[1]
print(motorcycles)
Removing an item using the pop() method
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
popped_motorcycle = motorcycles.pop()
print(motorcycles)
print(popped_motorcycle)
motorcycles = ['honda', 'yamaha', 'suzuki']
last_owned = motorcycles.pop()
print(f'The last motorcycle I owned was a {last_owned.title()}.')
Popping items from any position in a list
motorcycles = ['honda', 'yamaha', 'suzuki']
first_owned = motorcycles.pop(0)
print(f'The first motorcycle I owned was a {first_owned.title()}.')
Removing an item by value
motorcycles = ['honda', 'yamaha', 'suzuki', 'ducati']
print(motorcycles)
motorcycles.remove('ducati')
print(motorcycles)
motorcycles = ['honda', 'yamaha', 'suzuki', 'ducati']
print(motorcycles)
too_expensive = 'ducati'
motorcycles.remove(too_expensive)
print(motorcycles)
print(f'\nA {too_expensive.title()} is too expensive for me.')
The remove() method deletes only the first occurrence of the value you specify. If there’s a possibility the value appears more than once in the list, you’ll need to use a loop to make sure all occurrences of the value are removed.
TRY IT YOURSELF
- guest_list.py
- changing_guest_list.py
- more_guests.py
- shrinking_guest_list.py
3.3 Organizing a list
3.3.1 Sorting a list permanently with the sort() method
cars = ['bmw', 'audi', 'toyota', 'subaru']
cars.sort()
print(cars)
cars = ['bmw', 'audi', 'toyota', 'subaru']
cars.sort(reverse=True)
print(cars)
3.3.2 Sorting a list temporarily with the sorted() function
cars = ['bmw', 'audi', 'toyota', 'subaru']
print("Here is the original list:")
print(cars)
print("\nHere is the sorted list:")
print(sorted(cars))
print("Here is the original list again:")
print(cars)
3.3.3 Printing a list in reverse order
cars = ['bmw', 'audi', 'toyota', 'subaru']
print(cars)
cars.reverse()
print(cars)
3.3.4 Finding the length of a list
cars = ['bmw', 'audi', 'toyota', 'subaru']
len(cars)
TRY IT YOURSELF
- seeing_the_world.py
- dinner_guests.py
- every_function.py
3.4 Avoiding Index Errors When Working with Lists
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles[3])
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles[-1])
motorcycles = []
print(motorcycles[-1])
TRY IT YOURSELF
3.5 Summary
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