Python 中的 zip
python 的 zip() 函数详解:高效迭代多个可迭代对象
zip() 函数是 Python 中一个强大的工具,用于将多个可迭代对象(例如列表、元组等)组合成一个迭代器。它一次性从每个可迭代对象中取一个元素,并将这些元素打包成元组。当最短的可迭代对象耗尽时,迭代停止。由于 zip() 返回的是一个迭代器,而非列表,因此需要将其转换为列表 (list()) 才能通过索引访问其元素。
基本用法:
以下示例展示了 zip() 函数的基本用法,将三个列表 fruits、meats 和 vegetables 组合起来:
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fruits = ["apple", "orange", "banana", "kiwi", "lemon", "mango"]meats = ["chicken", "beef", "pork", "duck", "mutton"]vegetables = ["onion", "carrot", "garlic", "spinach", "eggplant"]zipped = zip(fruits, meats, vegetables)print(list(zipped)) # 将迭代器转换为列表以便查看结果# Output: [('apple', 'chicken', 'onion'), ('orange', 'beef', 'carrot'), ('banana', 'pork', 'garlic'), ('kiwi', 'duck', 'spinach'), ('lemon', 'mutton', 'eggplant')]# 迭代访问for fruit, meat, vegetable in zip(fruits, meats, vegetables): print(fruit, meat, vegetable)# Output:# apple chicken onion# orange beef carrot# banana pork garlic# kiwi duck spinach# lemon mutton eggplant
嵌套 zip() 的使用:
zip() 函数可以嵌套使用,以处理更复杂的迭代结构。以下示例展示了如何嵌套 zip() 函数,以及如何解包结果:
# 双层嵌套zipped_nested = zip(zip(fruits, meats), vegetables)print(list(zipped_nested))# Output: [(('apple', 'chicken'), 'onion'), (('orange', 'beef'), 'carrot'), (('banana', 'pork'), 'garlic'), (('kiwi', 'duck'), 'spinach'), (('lemon', 'mutton'), 'eggplant')]for (fruit, meat), vegetable in zip(zip(fruits, meats), vegetables): print(fruit, meat, vegetable)# Output:# apple chicken onion# orange beef carrot# banana pork garlic# kiwi duck spinach# lemon mutton eggplant# 三层嵌套 (更复杂的例子)fruits = ["Apple", "Orange", "Banana", "Kiwi", "Lemon", "Mango"]meats = ["Chicken", "Beef", "Pork", "Duck", "Mutton"]vegetables = ["Onion", "Carrot", "Garlic", "Spinach", "Eggplant"]zipped_triple = zip(zip(fruits, zip(meats)), vegetables)print(list(zipped_triple))# Output: [(('Apple', ('Chicken',)), 'Onion'), (('Orange', ('Beef',)), 'Carrot'), (('Banana', ('Pork',)), 'Garlic'), (('Kiwi', ('Duck',)), 'Spinach'), (('Lemon', ('Mutton',)), 'Eggplant')]for (fruit, (meat,)), vegetable in zip(zip(fruits, zip(meats)), vegetables): print(fruit, meat, vegetable)# Output:# Apple Chicken Onion# Orange Beef Carrot# Banana Pork Garlic# Kiwi Duck Spinach# Lemon Mutton Eggplant
请注意,在嵌套使用 zip() 时,解包元组的方式需要根据嵌套的层数进行调整。 这使得 zip() 函数在处理多个数据源或进行数据转换时非常灵活。
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