PyMongo-Python列表到MongoDB数据类型的转换

Question

我从以下请求中获得字符串格式的json响应：

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

样本输出：打印(结果(-对象类型=<类'列表'>

[
{
'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': ' '
}
]

需要先将所有这些字段转换为特定的数据类型，然后将其作为文档插入MongoDB。

1. 到期日期至日期/时间
2. 等于float((
3. 数量到int((

进行数据类型转换的有效方法是什么？

有没有想过，如果可能的话，也需要知道是否有任何空、null或空白字符串值，那么在数据类型转换过程中，如何用一些默认值替换它？

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(

新的列表输出应该看起来像：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

您可以这样做：

import datetime
input_lst = [
{
"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": " "
}
]
output_lst = []

for dct in input_lst:
tmp_dct = dct.copy()
# amount - float, qty - int4
try:
tmp_dct['amount'] = float(dct['amount'])
except:
pass
try:
tmp_dct['qty'] = int(dct['qty'])
except:
pass
try:
tmp_dct['exp_date'] = datetime.datetime.strptime(tmp_dct['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
output_lst.append(tmp_dct)
except:
pass

print(output_lst)

这更有效，因为您只循环一次。