如何在Python中打印字典中每个键的一个特定值？

Question

我有一个由 4 个键组成的字典，每个键有 3 个值。看起来像这样： d = {key1: (value1, value2, value), key2: (value1, value2, value), key3: (value1, value 2, value3)} 我想从所有键打印 value1 。我现在的做法是这样的：print (persons['1'][0])print(persons['2'][0])print (persons['3'][0])print(persons['4'][0])但我想有一种更简单的方法可以让我在一行中引用所有键？我还想找到所有键中的最高值2，以及所有键中值3的平均值。有人可以帮我解决这个问题吗？

Answer 1

您可以将您的字典转换为 DataFrame，这将使您的事情变得非常简单：

from pandas.DataFrame import from_dict

d = {'a':(1,2,3),'b':(4,5,6)}

d = from_dict(d, orient='index')

d[0] # print values of value1

d[1].max() # max of value2

d[2].mean() # mean of value3

Answer 2

您可以使用列表理解来实现此目的：

persons = {'1': (1,2,3), '2': (4,5,6), '3': (7,8,9)}

# First Value's

first_values = " ".join([str(x[0]) for x in persons.values()])

print(first_values)   # prints 1 4 7

# Max of second value's

max_value2 = max([x[1] for x in persons.values()])

print(max_value2)  # prints 8

# Average of value3's

third_values = [x[2] for x in persons.values()]

average_of_third_values = sum(third_values) / len(third_values)

# in case avoid zero division  : 

# average_of_third_values = sum(third_values) / (len(third_values) or 1)

print(average_of_third_values)  # prints 6

# to get value1 of values which has max value2

value1_of_max = [x[0] for x in persons.values() if x[1]==max_value2]

print(value1_of_max)  # prints [7]

# Its possible to be exist more than 1 person that has value2 which equals to max number, like so

# persons = {'1': (1,2,3), '2': (4,8,6), '3': (7,8,9)}

# so we print them as list

Answer 3

关于什么？

d = {

    "key1": (1,2,3),

    "key2": (3,4,5),

    "key4": (5,6,8),

}

[ print(val[0]) for _, val in d.items()]

Answer 4

关于什么？

d = {

    "key1": (1,2,3),

    "key2": (3,4,5),

    "key4": (5,6,8),

}

[ print(val[0]) for _, val in d.items()]

Answer 5

您可以使用for loop迭代：

d = {'test1': (1, 2, 3), 'test2': (4, 5, 6), 'test3': (7, 8, 9)}

for key in d.values():

    print(key[0])