Question

我有一个客户，他的期望是编写一个接受字典的函数convert()，然后返回与输入字典相同的结果。现在，从我的角度来看，我应该在convert()内进行检查，以使其与输入具有相同的键值，以便返回相同的值以通过assert。但是，他说那不是他所期望的，他取消了合同。他希望convert()函数返回没有模板进行检查的值（例如，不应该使用if record_id == 412029665_201012），这是什么魔术？

from typing import Dict


def convert(json_in: Dict) -> Dict:
    if json_in:
        if 'record_id' and 'irs_object_id' in json_in:
            record_id = json_in.get('record_id')
            irs_object_id = json_in.get('irs_object_id')
            if record_id == '412029665_201012' and irs_object_id == '201113199349201766':
                return json_in
    return dict()  # empty dictionary


def test_no_change_case():
    original: Dict = {
        "record_id": "412029665_201012",
        "irs_object_id": "201113199349201766",
    }
    expected: Dict = {
        "record_id": "412029665_201012",
        "irs_object_id": "201113199349201766",
    }
    actual: Dict = convert(original)
    assert actual == expected


test_no_change_case()

Answer 1

您始终可以执行assert original == expected，这将检查是否所有键和对应的值都匹配，如下所示，如果我更改了expected的键之一的值，或者添加了新的键值对，则断言失败

In [10]: from typing import Dict                                                                                                                                                                                      

In [11]:  original: Dict = { 
    ...:         "record_id": "412029665_201012", 
    ...:         "irs_object_id": "201113199349201766", 
    ...:     }                                                                                                                                                                                                        

In [12]: expected: Dict = { 
    ...:         "record_id": "412029665_201012", 
    ...:         "irs_object_id": "201113199349201766", 
    ...:     }                                                                                                                                                                                                        

In [13]: assert original == expected                                                                                                                                                                                  

In [14]: expected: Dict = { 
    ...:         "record_id": "412029665_201012", 
    ...:         "irs_object_id": "2011", 
    ...:     }                                                                                                                                                                                                        

In [15]: assert original == expected                                                                                                                                                                                  
---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
<ipython-input-15-573681974ca8> in <module>
----> 1 assert original == expected

AssertionError: 

In [16]: expected: Dict = { 
    ...:         "record_id": "412029665_201012", 
    ...:         "irs_object_id": "201113199349201766", 
    ...:         "key": "value" 
    ...:     }                                                                                                                                                                                                        

In [17]: assert original == expected                                                                                                                                                                                  
---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
<ipython-input-17-573681974ca8> in <module>
----> 1 assert original == expected

AssertionError

在原始代码中，实际上也不需要额外的if 'record_id' and 'irs_object_id' in json_in:检查，因为您使用的是dict.get方法，如果字典中不存在键，则该方法将返回None。

from typing import Dict


def convert(json_in: Dict) -> Dict:
    if json_in:
        #Removed the if test
        record_id = json_in.get('record_id')
        irs_object_id = json_in.get('irs_object_id')
        if record_id == '412029665_201012' and irs_object_id == '201113199349201766':
            return json_in
    return dict()  # empty dictionary


def test_no_change_case():
    original: Dict = {
        "record_id": "412029665_201012",
        "irs_object_id": "201113199349201766",
    }
    expected: Dict = {
        "record_id": "412029665_201012",
        "irs_object_id": "201113199349201766",
    }
    actual: Dict = convert(original)
    assert actual == expected


test_no_change_case()

编写一个无需指定键值即可接受字典的函数

1 个答案: