不可理解的类型:在pymongo中使用push时的“列表”
不可理解的类型:在pymongo中使用push时的“列表”
提问于 2022-07-20 08:17:11
我目前正在做一个网络抓取项目。我们的目标是每天恢复gaz站(900+)不同类型燃料的价格。如果价格发生变化，脚本将能够将新的价格附加到Mongodb数据库中。
收集的数据如下：
Price_post_api = {
"station_id": 31200009,
"price_detail": [
{
"fuel_id": 1,
"fuel_name": "Gazole",
"fuel_cost": 1.959,
"update_date": {
"$date": "2022-05-30T10:05:22Z"
}
},
{
"fuel_id": 2,
"fuel_name": "SP95",
"fuel_cost": 2.049,
"update_date": {
"$date": "2022-05-30T10:05:23Z"
}
},
{
"fuel_id": 5,
"fuel_name": "E10",
"fuel_cost": 2.009,
"update_date": {
"$date": "2022-05-30T10:05:23Z"
}
}
]
},我很难弄清楚如何基于$push字段正确地对Mongodb中的数据进行"fuel_cost"处理。这里是数据库中预期输出的一个示例。
Mongodb_price_data ={
"station_id": 31200009,
"price_detail": [
{
"fuel_id": 1,
"fuel_name": "Gazole",
"fuel_cost": 1.959,
"update_date": {
"$date": "2022-05-30T10:05:22Z"
}
},
{
"fuel_id": 1,
"fuel_name": "Gazole",
"fuel_cost": 35.87,
"update_date": {
"$date": "2022-05-31T10:09:22Z"
}
},
{
"fuel_id": 2,
"fuel_name": "SP95",
"fuel_cost": 2.049,
"update_date": {
"$date": "2022-05-30T10:05:23Z"
}
},
{
"fuel_id": 2,
"fuel_name": "Gazole",
"fuel_cost": 1.59,
"update_date": {
"$date": "2022-07-14T00:10:19Z"
}
},
{
"fuel_id": 5,
"fuel_name": "E10",
"fuel_cost": 2.009,
"update_date": {
"$date": "2022-05-30T10:05:23Z"
}
}
]
}到目前为止，我创建了以下函数：
def update_new_price(station_id, fuel_id, fuel_name, cost):
query = {'station_id':station_id, 'price_detail.fuel_id':fuel_id, 'price_detail.fuel_name':fuel_name,'price_detail.fuel_cost':cost}
new_value = {
'$push':{
'price_detail':{
[{'price_detail.fuel_id': fuel_id,'price_detail.fuel_name':fuel_name ,'price_detail.fuel_cost':cost}]
}}}
result = db[CL_PRICE].find(query)
if not list(result):
db[CL_PRICE].update_one(query,new_value,upsert= True)
print('new value added')
else:
print('Already exists')一旦我运行我的代码，我就会收到一条错误消息。
'price_detail':{
TypeError: unhashable type: 'list'你知不知道为什么我能修好它？
回答 1
Stack Overflow用户
发布于 2022-07-28 02:07:36
我想你需要在那里拆下额外的弧形支撑。
而不是
'price_detail':{
[{'price_detail.fuel_id': fuel_id,'price_detail.fuel_name':fuel_name ,'price_detail.fuel_cost':cost}]
}它应该是商店
'price_detail': [
{'price_detail.fuel_id': fuel_id,'price_detail.fuel_name':fuel_name ,'price_detail.fuel_cost':cost}
]实际上，您正在尝试创建一个由一个元素组成的集合，该元素是一个列表。并且set只能包含列表不包含的可选对象。
一个最小的可重复的例子是
>>> {[1, 2, 3]}
Traceback (most recent call last):
Input In [2] in <cell line: 1>
{[1, 2, 3]}
TypeError: unhashable type: 'list'中间没有{}的:是创建集合的语法。为了清晰起见，下面是一些创建集合的正确方法的示例。
>>> {(1, 2, 3)} # a set containing a single tuple
{(1, 2, 3)}
>>> {*[1, 2, 3]} # a set of three elements created from a list
{1, 2, 3}
>>> {1, 2, 3} # a set created from three values
{1, 2, 3}
>>> {x for x in range(1, 4)} # a set comprehension expression
{1, 2, 3}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/73048139
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