python基础-operating_list_python operating

 
# 1.遍历整个列表
magicians = ['alice', 'david', 'carolina']
for magician in magicians:
    print(magician)
 
for magician in magicians:
    print(magician.title() + ", that was a great trick!")
    print("I can't wait to see your next trick, " + magician.title() + ".\n")
 
# 2.避免缩进错误
# 2.1忘记缩进
# magicians = ['alice', 'david', 'carolina']
# for magician in magicians:
# print(magician)
 
# 2.2忘记缩进额外的代码行
# for magician in magicians:
#     print(magician.title() + ", that was a great trick!") # 因为此行缩进，所以不报错
# print("I can't wait to see your next trick, " + magician.title() + ".\n")  # 最后一个magician为carolina
 
# 2.3不必要的缩进
# message = 'hello'
#     print(message)
 
# 2.4遗漏了冒号
# for magician in magicians
#     print(magician)
 
# P50动手试一试
# 4-1
pizzas = ['A', 'B', 'C']
for pizza in pizzas:
    print('I like %s pizza' % pizza)
print('I really love pizza')
 
# 4-2
animals = ['A', 'B', 'C']
for animal in animals:
    print('A %s would make a great pet.' % animal)
print('Any of these animals would make a great pet!')
 
 
# 3创建数值列表
# 3.1使用range()函数，产生的结果:{x belongs with Z : lower <= x < upper}
# 使用range()时，如果输出不符合预期，请尝试将指定的值加1或减1。
for value in range(1, 5):
    print(value)
 
# 3.2使用range()创建数字列表
numbers = list(range(1, 5))
print(numbers)
# 打印1~10内的偶数：
even_numbers = list(range(2, 11, 2))
print(even_numbers)
 
# 创建一个包含前10个整数的平方的列表
squares = []
for value in range(1, 11):
    # square = value ** 2  # 两个*表示乘方运算
    # squares.append(square)
    squares.append(value ** 2)
print(squares)
 
# 3.3对数字列表执行统计计算
digits = list(range(0, 10))
print(digits)
print(min(digits))
print(max(digits))
print(sum(digits))
 
# 3.4列表解析：列表解析将for循环和创建新元素的代码合并成一行，并自动附加新元素。
'''
首先指定一个描述性的列表名，如squares； 然后，指定一个左方括号，
并定义一个表达式，用于生成你要存储到列表中的值。在这个示例中，表达式为value**2，
它计算平方值。接下来，编写一个for循环， 用于给表达式提供值，再加上右方括号。
'''
squares = [value**2 for value in range(1, 11)]
print(squares)
 
# P54动手试一试
# 4-3
for i in range(1, 21):
    print(i)
# 4-4
# for i in range(1, 1000001):
#     print(i)
# 4-5
numbers = list(range(1, 1000001))
print(min(numbers))
print(max(numbers))
print(sum(numbers))
# 4-6
odds = list(range(1, 20, 2))
for odd in odds:
    print(odd) 
# 4-7
threes = []
for i in range(3, 30):
    if i % 3 == 0:
        threes.append(i)
print(threes)
# 4-8/9
nums = [value ** 3 for value in range(1, 11)]
print(nums)
 
 
# 4.使用列表的一部分
# 4.1切片，要创建切片，可指定要使用的第一个元素和最后一个元素的索引。
players = ['charles', 'martina', 'michael', 'florence', 'eli']
print(players)
print(players[0:3])  # 前三个
print(players[1:4]) # 第2-4个
# 如果你没有指定第一个索引或最后一个索引， Python将自动从列表开头开始或结尾终止：
print(players[:4])
print(players[1:])
 
print(players[-3:])  # 后三个
print(players[-2:]) # 后两个
 
# 4.2遍历切片,如果要遍历列表的部分元素，可在for循环中使用切片。
for player in players[:3]:
    print(player) # 前3个
 
 
# 4.3复制列表
my_foods = ['pizza', 'falafel', 'carrot cake'] # 
friend_foods = my_foods[:]  # 在不指定任何索引的情况下从列表my_foods中提取一个切片，复制一个切片
# friend_foods = my_foods # 浅复制，指向同一个列表
print(friend_foods)
my_foods.append('a')
print('确实是两个列表')
print(my_foods)
print(friend_foods)
 
# P58动手试一试
# 4-10
print('the list is:',players)
print('The first three items in the list are:', players[:3])
print('Three items  from the middle of the list are:', players[1:4])
print('The last three items in the list are:', players[-3:])
# 4-11
friend_pizzas = pizzas[:]
print(friend_pizzas)
print(pizzas)
pizzas.append('D')
friend_pizzas.append('F')
print('My favorite pizzas are:')
for pizza in pizzas:
    print(pizza)
print("My friend's favorite pizza are:")
for pizza in friend_pizzas:
    print(pizza)
 
 
# 5.元组
# Python将不能修改的值称为不可变的，而不可变的列表被称为元组。使用圆括号来标识
 
# 5.1定义元祖
dimensions = (200, 50)
print(dimensions)
# 5.2遍历元组中的所有值
for dimension in dimensions:
    print(dimension)
 
# 5.3修改元组变量,虽然不能修改元组的元素，但可以给存储元组的变量赋值
dimensions = (300, 400)
print(dimensions)
 
# P60动手试一试
#4-13
foods = ('A', 'B', 'C', 'D', 'E')
for food in foods:
    print(food)
# foods[0] = 'C'
foods = ('X', 'Y', 'C', 'D', 'E')
for food in foods:
    print(food)
 
 
# 6.设置代码格式：PEP8格式指南