python list

列表特性

• 元素类型不必相同

空列表

empty = []

列表示例

• 纯数字

numbers = [1, 2, 3, 4, 5]

• 纯字符串

strings = ['apple', 'banana', 'orange']

• 混合类型

mixed = [12, 55, 'China', {'age': 25}]

• 列表嵌套

nested = [10, 20, [1, 2, 3, 4]]

访问元素

numbers = [10, 20, 30, 40, 50]
numbers[0] # 10

删除元素

numbers = [10, 20, 30, 40, 50]
del numbers[1] # [10, 30, 40, 50]

列表长度

numbers = [10, 20, 30, 40, 50]
len(numbers) # 5

列表最大值和最小值

numbers = [10, 20, 30, 40, 50]
max(numbers) # 50
min(numbers) # 10

列表遍历

• 只读遍历

numbers = [10, 20, 30, 40, 50]
for number in numbers:
    print(number)

• 修改遍历

numbers = [10, 20, 30, 40, 50]
for index in range(len(numbers)):
    numbers[index] = numbers[index] * 2

列表合并

a = [1, 2, 3]
b = [4, 5, 6]
c = a + b # [1, 2, 3, 4, 5, 6]

列表重复

x = [1, 2, 3] * 2 # [1, 2, 3, 1, 2, 3]

成员检查

1 in [1, 2, 3] # True

列表分片

列表方法

• 末尾添加新元素

• 清空列表

• 统计元素个数