Python编程从入门到实践（3）学习笔记-列表，切片，元组

第四章 列表，切片，元组

# 第四章 操作列表

magicians = ['alice', 'david', 'carolina']
for magician in magicians:
    print(magician)

for magician in magicians:
    print(magician.title() + ",that was a great trick!")
    print("循环内语句，前面有空格缩进")

for magician in magicians:
    print(magician.title() + ",that was a great trick!")
print("循环外语句")

# 创建数字列表 只有1,2,3,4 没有5,5是开区间
# start是闭区间 end是开区间
for value in range(1, 5):
    print(value)

# 转list列表 [1, 2, 3, 4, 5]
numbers = list(range(1, 6))
print(numbers)

# 指定步长的list [2, 4, 6, 8, 10]
even_numbers = list(range(2, 11, 2))
print(even_numbers)

# [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
squares = []
for value in range(1, 11):
    squares.append(value ** 2)
print(squares)

# 上面等价于一行代码
squares = [value ** 2 for value in range(1, 11)]
print(squares)

# 列表的统计
digits = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
print(min(digits))
print(max(digits))
print(sum(digits))

# 切片 有点像substring
players = ['charles', 'martina', 'michael', 'florence', 'eli']
# ['charles', 'martina', 'michael']
print(players[0:3])
# ['martina', 'michael', 'florence']
print(players[1:4])
# ['charles', 'martina', 'michael', 'florence']
print(players[:4])
# ['michael', 'florence', 'eli']
print(players[2:])
# 最后3名队员的名字
# ['michael', 'florence', 'eli']
print(players[-3:])

# 遍历切片 前3名队员
for play in players[:3]:
    print(play.title())

# 复制列表 值拷贝
my_foods = ['pizza','falafel','carrot cake']
friend_foods = my_foods[:]
print("my favorite foods are:")
print(my_foods)
print("my friend favorite foods are:")
print(friend_foods)

# 引用
friend_foods = my_foods

#元组
dimensions = (200,50)
print(dimensions[0])
print(dimensions[1])
#修改值禁止
#dimension[0]=250

# 遍历元组
for dimension in dimensions:
    print(dimension)

# 修改元组值
dimensions = (200,50)
dimensions = (400,100)
for dimension in dimensions:
    print(dimension)