如何使用dict理解实现以下结果?

时间:2019-03-13 18:41:21

标签: python python-3.x dictionary list-comprehension

你好,我想从字典中获取所有的'Integer'值:

array_test = [{ "result1" : "date1",  "type" : "Integer"},{ "result1" : "date2", "type" : "null"}]

我尝试过:

test = {'result1':array_test['result1'] for element in array_test if array_test['type'] == "Integer"}

但是我遇到了这个错误:

>>> test = {'result1':array_test['result1'] for element in array_test if array_test['type'] == "Integer"}

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in <dictcomp>
TypeError: list indices must be integers or slices, not str
>>> 
>>> 

因此,我想感谢支持实现以下输出

test = [{ "result1" : "date1",  "type" : "Integer"}]

1 个答案:

答案 0 :(得分:2)

您需要一个列表理解,而不是字典理解:

array_test = [{ "result1" : "date1",  "type" : "Integer"},{ "result1" : "date2", "type" : "null"}]

test = [x for x in array_test if x['type'] == 'Integer']
# [{'result1': 'date1', 'type': 'Integer'}]

为什么?因为所需的输出是一个列表(词典列表)。