如何正确迭代列表和字典值？答案

【问题标题】：how to properly iterate over a list and a dictionary values?如何正确迭代列表和字典值？
【发布时间】：2021-03-31 19:58:12
【问题描述】：

我试图先遍历列表，然后遍历字典值：

这个想法是print() 列表元素和字典值之间的所有可能组合。

这是我目前得到的：

countries = ["Mexico", "Brasil", "Argentina"]
job_catalog = {"operations director":["director de operaciones", "director of business operations"]}

for country in countries:
    for job_title in job_catalog:
           report_name=str(job_catalog.values())+'-'+country
           print(report_name)

控制台输出：

dict_values([['director de operaciones', 'director of business operations']])-Mexico
dict_values([['director de operaciones', 'director of business operations']])-Brasil
dict_values([['director de operaciones', 'director of business operations']])-Argentina

预期输出：

#director de operaciones-Mexico
#director de operaciones-Brasil
#director de operaciones-Argentina
#director of business operations-Mexico
#director of business operations- Brasil
#director of business operations-Argentina

我错过了什么？还有其他更简单的方法来完成这项任务吗？

【问题讨论】：

标签： python list loops dictionary

【解决方案1】：

您应该迭代 dict 值：

countries = ["Mexico", "Brasil", "Argentina"]
job_catalog = {"operations director": ["director de operaciones", "director of business operations"]}

for country in countries:
    for job_titles in job_catalog.values():
        for job_title in job_titles:
            report_name = f"{job_title}={country}"
            print(report_name)

输出：

director de operaciones=Mexico
director de operaciones=Brasil
director de operaciones=Argentina
director of business operations=Mexico
director of business operations=Brasil
director of business operations=Argentina

您可以遍历 dict's values 和 dict's keys：

d = {"a": "b", "c": "d"}

for key in d.keys():
    print(key)

for value in d.values():
    print(key)

for key, value in d.items():
    print(key, value)

【讨论】：

【解决方案2】：

您可以使用itertools.product：

from itertools import product


countries = ["Mexico", "Brasil", "Argentina"]
job_catalog = {
    "operations director": [
        "director de operaciones",
        "director of business operations",
    ]
}

for a, b in product(job_catalog["operations director"], countries):
    print("#{}-{}".format(a, b))

打印：

#director de operaciones-Mexico
#director de operaciones-Brasil
#director de operaciones-Argentina
#director of business operations-Mexico
#director of business operations-Brasil
#director of business operations-Argentina

【讨论】：