使用多个列表中的值设置Python字符串格式

Question

我尝试使用多个列表中的值格式化字符串。以下是伪代码，但应该给出预期输出的概念。结果是每个列表中每一项的组合：每个人都喜欢在做所有爱好的同时吃所有的水果。那么如何在python中实现这一点呢？在

应该有len(names)*len(fruits)*len(hobbies)个可能性（在我的例子中是64个）

names = ['tom','marry','jessica','john']
fruits = ['oranges','apples','grapes','bananas']
hobbies = ['dancing','sitting','bicycling','watching tv']

print '%(name)s likes to eat %(fruit)s while %(hobby)s \n'
       % {'name':names, 'fruit':fruits, 'hobby':hobbies}

Answer 1

只需使用for循环：

names = ['tom','marry','jessica','john']
fruits = ['oranges','apples','grapes','bananas']
hobbies = ['dancing','sitting','bicycling','watching tv']

for name in names:
    for fruit in fruits:
        for hobby in hobbies:
            print '%(name)s likes to eat %(fruit)s while %(hobby)s' \
                   % {'name': name, 'fruit': fruit, 'hobby': hobby}

但是，如果你问我，我总觉得用^{}会让一切看起来更好：

^{pr2}$

Answer 2

如果我理解你的“输出将是每个列表中每一项的组合：每个人在做每一项爱好时都喜欢所有的水果”这句话，你就想要所有可能的组合。可以使用嵌套循环的方式执行此操作：

names = ['tom','mary','jessica','john']
fruits = ['oranges','apples','grapes','bananas']
hobbies = ['dancing','sitting','bicycling','watching tv']

for name in names:
    for fruit in fruits:
        for hobby in hobbies:
            print '%(name)s likes to eat %(fruit)s while %(hobby)s' % {'name':name, 'fruit':fruit, 'hobby':hobby}

产生

^{pr2}$

或者您可以使用itertools模块，该模块有一个函数product，该函数提供了输入列表的所有可能组合：

import itertools

for name, fruit, hobby in itertools.product(names, fruits, hobbies):
    print '%(name)s likes to eat %(fruit)s while %(hobby)s' % {'name':name, 'fruit':fruit, 'hobby':hobby}

Answer 3

itertools模块提供product函数，该函数生成所有可能的元组：

>>> from itertools import product
>>> names = ['tom','marry','jessica','john']
>>> fruits = ['oranges','apples','grapes','bananas']
>>> hobbies = ['dancing','sitting','bicycling','watching tv']
>>> for n, f, h in product(names, fruits, hobbies):
...     print '%s likes to eat %s while %s' % (n, f, h)

也可以直接使用元组：

^{pr2}$