操作列表
遍历整个元素
magicians = ['alice', 'david', 'canlina']
for magician in magicians:
print(magician)
打印 alice david canlina
在 for 循环中执行更多的操作
magicians = ['alice', 'david', 'canlina']
for magician in magicians:
print(f"{magician.title()}, that was a great trick!")
打印 alice, that was a great trick!
david, that was a great trick!
canlina, that was a great trick!
在 for 循环结束后中执行一些操作
magicians = ['alice', 'david', 'canlina']
for magician in magicians:
print(f"{magician.title()}, that was a great trick!")
print('Thank you, everyone. That was a great magic show!')
打印 alice, that was a great trick!
david, that was a great trick!
canlina, that was a great trick!
Thank you, everyone. That was a great magic show!
避免缩进错误
忘记缩进
magicians = ['alice', 'david', 'canlina']
for magician in magicians:
print(f"{magician.title()}, that was a great trick!")
python 这里将会报错，提示你需要缩进
忘记缩进额外的代码行
magicians = ['alice', 'david', 'canlina']
for magician in magicians:
print(f"{magician.title()}, that was a great trick!")
print(f"I can't wait to see your next trick, {magician.title()}")
打印
alice, that was a great trick!
david, that was a great trick!
canlina, that was a great trick!
I can’t wait to see your next trick, Canlina
不必要的缩进
message = 'Hello World'
print(f"{message}")
python 会报错，提示这里无需缩进
遗漏冒号
magicians = ['alice', 'david', 'canlina']
for magician in magicians
print(f"{magician.title()}, that was a great trick!")
python 会报错，提示缺少冒号
创建数值列表
使用 range() 函数
for value in range(1, 5):
print(value)
打印 1 2 3 4
使用 range() 创建数值列表
list(range(1, 5))
打印 [1, 2, 3, 4]
list(range(1, 5, 2))
打印 [1, 3]
对数值列表执行简单的统计计算
min() 计算列表中的最小值
max() 计算列表中的最大值
sum() 计算列表中的总数
列表推导式
squares = [value**2 for value in range(1, 11)]
print(squares)
打印 [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
使用列表中的一部分
切片
指定使用的第一个元素和最后一个元素的索引（包头不包尾，可省略参数）
plaryers = ['charles', 'martina', 'michael', 'florence', 'eli']
print(plaryers[0:3])
打印 [‘charles’, ‘martina’, ‘michael’]
遍历切片
plaryers = ['charles', 'martina', 'michael', 'florence', 'eli']
print(plaryers[0:3])
for player in plaryers[0:3]:
print(player.title())
打印 Charles Martina Michael
复制列表
创建的是一个列表的副本，不是同一个引用
plaryers = ['charles', 'martina', 'michael', 'florence', 'eli']
print(plaryers)
copied_players = plaryers[:]
print(copied_players)
打印
[‘charles’, ‘martina’, ‘michael’, ‘florence’, ‘eli’] [‘charles’, ‘martina’, ‘michael’, ‘florence’, ‘eli’]
元组
使用圆括号定义元组（不能修改元组的元素）
dimensions = (200, 50)
print(dimensions[0])
print(dimensions[1])
打印 200 50
遍历元组中的所有值
dimensions = (200, 50)
for dimension in dimensions:
print(dimension)
打印 200 50
修改元组变量
dimensions = (200, 50)
for dimension in dimensions:
print(dimension)
dimensions = (201, 51)
for dimension in dimensions:
print(dimension)
上述操作是合法的