我试着阅读尽可能多的答案，以防止给出重复的答案。然而，如果你正在处理一个包含在列表中的值的字典，并且如果你想获得具有特定元素的键，你可以这样做:

d = {'Adams': [18, 29, 30],
     'Allen': [9, 27],
     'Anderson': [24, 26],
     'Bailey': [7, 30],
     'Baker': [31, 7, 10, 19],
     'Barnes': [22, 31, 10, 21],
     'Bell': [2, 24, 17, 26]}

现在让我们找到值为24的名称。

for key in d.keys():    
    if 24 in d[key]:
        print(key)

这也适用于多个值。

以下是我对这个问题的看法。：） 我刚刚开始学习Python，所以我称之为:

“初学者可以理解的”解决方案。

#Code without comments.

list1 = {'george':16,'amber':19, 'Garry':19}
search_age = raw_input("Provide age: ")
print
search_age = int(search_age)

listByAge = {}

for name, age in list1.items():
    if age == search_age:
        age = str(age)
        results = name + " " +age
        print results

        age2 = int(age)
        listByAge[name] = listByAge.get(name,0)+age2

print
print listByAge

.

#Code with comments.
#I've added another name with the same age to the list.
list1 = {'george':16,'amber':19, 'Garry':19}
#Original code.
search_age = raw_input("Provide age: ")
print
#Because raw_input gives a string, we need to convert it to int,
#so we can search the dictionary list with it.
search_age = int(search_age)

#Here we define another empty dictionary, to store the results in a more 
#permanent way.
listByAge = {}

#We use double variable iteration, so we get both the name and age 
#on each run of the loop.
for name, age in list1.items():
    #Here we check if the User Defined age = the age parameter 
    #for this run of the loop.
    if age == search_age:
        #Here we convert Age back to string, because we will concatenate it 
        #with the person's name. 
        age = str(age)
        #Here we concatenate.
        results = name + " " +age
        #If you want just the names and ages displayed you can delete
        #the code after "print results". If you want them stored, don't...
        print results

        #Here we create a second variable that uses the value of
        #the age for the current person in the list.
        #For example if "Anna" is "10", age2 = 10,
        #integer value which we can use in addition.
        age2 = int(age)
        #Here we use the method that checks or creates values in dictionaries.
        #We create a new entry for each name that matches the User Defined Age
        #with default value of 0, and then we add the value from age2.
        listByAge[name] = listByAge.get(name,0)+age2

#Here we print the new dictionary with the users with User Defined Age.
print
print listByAge

.

#Results
Running: *\test.py (Thu Jun 06 05:10:02 2013)

Provide age: 19

amber 19
Garry 19

{'amber': 19, 'Garry': 19}

Execution Successful!

a = {'a':1,'b':2,'c':3}
{v:k for k, v in a.items()}[1]

或更好的

{k:v for k, v in a.items() if v == 1}

for name in mydict:
    if mydict[name] == search_age:
        print(name) 
        #or do something else with it. 
        #if in a function append to a temporary list, 
        #then after the loop return the list

试试下面的一行代码来反转字典:

reversed_dictionary = dict(map(reversed, dictionary.items()))

我们可以通过以下方法得到dict的Key:

def getKey(dct,value):
     return [key for key in dct if (dct[key] == value)]