PyMongo - Python 列表到 MongoDB 数据类型的转换

Question

我从请求中获取字符串格式的 json 响应，如下所示：

results = requests.request("POST", url, data=json.dumps(payload), headers=header).json()['product']

示例输出： print(results) - object type = <class ' list '>

[

{

 'id': '123456',

 'product': 'XYZ',

 'exp_date': '03/01/2020',

 'amount': '30.5',

 'qty': '1'

},

{

 'id': '789012',

 'product': 'ABC',

 'exp_date': '04/15/2020',

 'amount': '22.57',

 'qty': '3'

},

{

 'id': '56789',

 'product': 'AAA',

 'exp_date': '03/29/2020',

 'amount': '',

 'qty': ' '

}

]

需要首先将所有这些字段转换为特定的数据类型，然后作为文档插入到 MongoDB 中。

1. exp_date 到日期/时间

2. 金额为float()

3. 数量 转int()

进行数据类型转换的有效方法是什么？

正在考虑是否可能像下面这样，还需要知道是否有任何空、空或空白字符串值，那么如何在数据类型转换期间将其替换为某些默认值？

new_result = []

for i in enumerate(results):

    i[exp_date] = datetime.strptime(i[exp_date],'%m/%d%Y').replace(hour=0, minute=0, second=0, microsecond=0)                         #check for empty/null/blank values and replace with default date

    new_result.append(i[exp_date])

for i in enumerate(results):

    i[amount] = float(i[amount])   #check for empty/null/blank values and replace with 0.00

    new_result.append(i[amount])

for i in enumerate(results):

    i[qty] = int(i[qty])           #check for empty/null/blank values and replace with 0

    new_result.append(i[qty])

db.collection.insert_many(new_result)

新列表输出应如下所示：print(new_result)

[

{

 "id": "123456",

 "product": "XYZ",

 "exp_date": 2020-03-01 00:00:00,

 "amount": 30.5,

 "qty": 1

},

{

 "id": "789012",

 "product": "ABC",

 "exp_date": 2020-04-15 00:00:00,

 "amount": 22.57,

 "qty": 3

},

{

 "id": "56789",

 "product": "AAA",

 "exp_date": 2020-03-29 00:00:00,

 "amount": 0.0,

 "qty": 0

}

]

Answer 1

你可以这样做：import datetimeinput_lst = [{&nbsp;"id": "123456",&nbsp;"product": "XYZ",&nbsp;"exp_date": "03/01/2020",&nbsp;"amount": "30.5",&nbsp;"qty": "1"},{&nbsp;"id": "789012",&nbsp;"product": "ABC",&nbsp;"exp_date": "04/15/2020",&nbsp;"amount": "22.57",&nbsp;"qty": "3"},{&nbsp;"id": "56789",&nbsp;"product": "AAA",&nbsp;"exp_date": "03/29/2020",&nbsp;"amount": "",&nbsp;"qty": " "}]output_lst = []for dct in input_lst:&nbsp; &nbsp; tmp_dct = dct.copy()&nbsp; &nbsp; # amount - float, qty - int4&nbsp; &nbsp; try:&nbsp; &nbsp; &nbsp; &nbsp; tmp_dct['amount'] = float(dct['amount'])&nbsp; &nbsp; except:&nbsp; &nbsp; &nbsp; &nbsp; pass&nbsp; &nbsp; try:&nbsp; &nbsp; &nbsp; &nbsp; tmp_dct['qty'] = int(dct['qty'])&nbsp; &nbsp; except:&nbsp; &nbsp; &nbsp; &nbsp; pass&nbsp; &nbsp; try:&nbsp; &nbsp; &nbsp; &nbsp; tmp_dct['exp_date'] = datetime.datetime.strptime(tmp_dct['exp_date'],'%m/%d/%Y').replace(hour=0, minute=0, second=0, microsecond=0)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;#check for empty/null/blank values and replace with default date&nbsp; &nbsp; &nbsp; &nbsp; output_lst.append(tmp_dct)&nbsp; &nbsp; except:&nbsp; &nbsp; &nbsp; &nbsp; passprint(output_lst)这更有效，因为您只循环一次。