通过遍历列表中的值来获取字典值 | Python

Question

我想做一个 function search_subject来搜索一个主题并找到该主题的相应教授，例如{professor1: [biology, maths], professor2: [gymnastics, arts]如果你在被要求输入时输入biology ，你会得到professor1

我试图避免为这个项目制作一个嵌套的字典，但我被卡住了，感谢任何帮助

Answer 1

遍历professors.items()并检查主题

professors = {'professor1' : ['biology', 'maths'],  'professor2' : ['gymnastics', 'arts']}

def search_subject(target):
    for key, val in professors.items():
        if target in val:
            return key
    return False

print(search_subject('biology'))

Output： professor1 1

Answer 2

请记住引用字符串。
翻转字典。
使用倒排字典按学科查找教授。

professor_to_subjects = {'professor1' : ['biology', 'maths'],
                         'professor2' : ['gymnastics', 'arts'], }

subject_to_professor = {}

for professor, subjects in professor_to_subjects.items():
    for subject in subjects:
        subject_to_professor[subject] = professor

print(subject_to_professor)
# {'biology': 'professor1', 'maths': 'professor1', 'gymnastics': 'professor2', 'arts': 'professor2'}

print(subject_to_professor['biology'])
# professor1