问题描述
我有一个字典列表，我正在尝试循环并需要检查 'pmdruleid' 中的 rulenames 是否与 'pmdruleid' 中的任何 activeclientrulelist 匹配。我正在使用以下代码并且每次都收到 None。下面的代码在循环中检查相应的索引值，而不是检查列表中的任何匹配值：
activeclientrulelist = [{'pmdruleid': 112,'createdby': 'Ad hoc Script - PHARMMD\\Jake.Woods','updatedby': None,'transferstatuscode': 1},{'pmdruleid': 10160,{'pmdruleid': 10016,{'pmdruleid':111,{'pmdruleid': 111,{'pmdruleid': 10020,'transferstatuscode': 1}]
rulenames = [{'pmdruleid': 112,'transferstatuscode': 1}]
if len(activeclientrulelist) > 0:
for rule in rulenames:
matching_active_client_rule_items = [y for y in activeclientrulelist if y['pmdruleid'] == rule['pmdruleid']
预期输出
[{'pmdruleid': 112,'transferstatuscode': 1}]
解决方法
如果你想找到两个字典列表之间的交集，你可以这样做：
res = [x for x in activeclientrulelist if x in rulenames]
而 res 将是：
[{'pmdruleid': 112,'createdby': 'Ad hoc Script - PHARMMD\\Jake.Woods','updatedby': None,'transferstatuscode': 1},{'pmdruleid': 10160,'transferstatuscode': 1}]
如果您只想考虑您可以执行的 pmdruleid 键，则无需在列表理解之外循环 rulenames，否则您会覆盖结果：
[x for x in activeclientrulelist for y in rulenames if x['pmdruleid'] == y['pmdruleid']]
问题似乎是每次都刷新列表，所以我将其更改如下：
matching_active_client_rule_items=[]
if len(activeclientrulelist) > 0:
for rule in rulenames:
matching_active_client_rule_items.extend( [y for y in activeclientrulelist if y['pmdruleid'] == rule['pmdruleid']])
print(matching_active_client_rule_items)
我在上面定义了一个空列表，并通过正确的项目扩展了列表。
,您当前的代码有几个问题：
- 在第
]行的末尾缺少一个matching_active_client_rule_items = [y for y in activeclientrulelist if y['pmdruleid'] == rule['pmdruleid']。 - 使用此行：
matching_active_client_rule_items = [y for y in activeclientrulelist if y['pmdruleid'] == rule['pmdruleid']，您将覆盖列表对象，其中仅包含rulenames中最后一项的输出。
您需要创建一个列表并对其进行扩展以修复代码：
matching_active_client_rule_items = []
if len(activeclientrulelist) > 0:
for rule in rulenames:
matching_active_client_rule_items.extend([y for y in activeclientrulelist if y['pmdruleid'] == rule['pmdruleid']])
虽然这有效，但您应该使用如下列表理解方法来获取两个列表的交集：
matching_active_client_rule_items = [x for x in activeclientrulelist for y in rulenames if x['pmdruleid'] == y['pmdruleid']]
尝试以下操作：
activeclientrulelist = [{'pmdruleid': 112,{'pmdruleid': 10016,{'pmdruleid':111,{'pmdruleid': 111,{'pmdruleid': 10020,'transferstatuscode': 1}]
rulenames = [{'pmdruleid': 112,{'pmdruleid': 101,'transferstatuscode': 1}]
result = [check for check in rulenames for rule in activeclientrulelist if rule['pmdruleid']==check['pmdruleid']]
print(result)
在这种情况下，rulenames: 'pmdruleid': 101 不属于 activeclientrulelist 中的字典，因此省略！