003_列表简介_list_intro.py

# 列表 由一系列按特定顺序排列的元素组成。
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles)

# 访问列表元素
print(bicycles[0])
print(bicycles[0].title())

# 索引从0而不是1开始
print(bicycles[1])
print(bicycles[3])
print(bicycles[-1])  # 访问最后一个；

# 使用列表中的各个值
message = "My first bicycle was a " + bicycles[0].title() + "."
print(message)

# 修改、 添加和删除元素

# 修改列表元素
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
motorcycles[0] = 'ducati'
print(motorcycles)

# 在列表中添加元素
motorcycles.append('ducati')  # 在列表末尾添加元素
print(motorcycles)

motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)

motorcycles.insert(0, 'ducati')  # 在列表中插入元素
print(motorcycles)

# 从列表中删除元素
motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
del motorcycles[0]  # 使用del 语句删除元素
print(motorcycles)
del motorcycles[1]
print(motorcycles)

motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles)
popped_motorcycle = motorcycles.pop()  # 使用方法pop() 删除元素
print(motorcycles)
print(popped_motorcycle)

first_owned = motorcycles.pop(0)  # 弹出列表中任何位置处的元素
print('The first motorcycle I owned was a ' + first_owned.title() + '.')

# 如果你要从列表中删除一个元素， 且不再以任何方式使用它， 就使用del 语句；
# 如果你要在删除元素后还能继续使用它， 就使用方法pop() 。

motorcycles = ['honda', 'yamaha', 'suzuki', 'ducati']
print(motorcycles)
motorcycles.remove('ducati')  # 根据值删除元素
print(motorcycles)

motorcycles = ['honda', 'yamaha', 'suzuki', 'ducati']
print(motorcycles)
too_expensive = 'ducati'
motorcycles.remove(too_expensive)
print(motorcycles)
print("\nA " + too_expensive.title() + " is too expensive for me.")
# 方法remove() 只删除第一个指定的值。 如果要删除的值可能在列表中出现多次， 就需要使用循环来判断是否删除了所有这样的值。


cars = ['bmw', 'audi', 'toyota', 'subaru']
cars.sort()  # 使用方法sort() 对列表进行永久性排序
print(cars)

cars = ['bmw', 'audi', 'toyota', 'subaru']
cars.sort(reverse=True)
print(cars)

cars = ['bmw', 'audi', 'toyota', 'subaru']
print("\nHere is the original list:")
print(cars)  # 使用函数sorted() 对列表进行临时排序
print("\nHere is the sorted list:")
print(sorted(cars))
print("\nHere is the original list again:")
print(cars)

cars = ['bmw', 'audi', 'toyota', 'subaru']
print(cars)
cars.reverse()  # 倒着打印列表
print(cars)

print(len(cars))  # 确定列表的长度