Python3操作MongoDB数据库

0. 写在前面

• Linux：Ubuntu Kylin 16.04
• MongoDB：MongoDB3.2.7
• Python：Anaconda With Python3.7

1. 安装开源驱动库pymongo

pymongo驱动程序可以直接连接MongoDB数据库

zhangsan@node01:~$ conda create -n py39 python = 3.9
zhangsan@node01:~$ conda activate py39
(py39) zhangsan@node01:~$ python3 -m pip install pymongo
Collecting pymongo
  Downloading pymongo-4.2.0-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (479 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 479.2/479.2 kB 37.7 kB/s eta 0:00:00
Installing collected packages: pymongo
Successfully installed pymongo-4.2.0

(py39) zhangsan@node01:~$ vim pyinsert.py

from pymongo import MongoClient
from random import randint
import datetime
client = MongoClient('localhost',27017)
db = client.taobao
order = db.order_info
status = ['A','B','C']
cust_id = ['A123','B123','C123']
price = [500,200,250,300]
sku = ['mmm','nnn']
for i in range(1,100):
    items = []
    item_count =randint(2,6)
    for n in range(item_count):
        items.append({"sku":sku[randint(0,1)],"qty":randint(1,10),"price":randint(0,5)})
        new = { "status":status[randint(0,2)], "cust_id":cust_id[randint(0,2)], "price":price[randint(0,3)], "ord_date":datetime.datetime.utcnow(), "items":items }
        print(new)
        order.insert_one(new)
print(order.estimated_document_count())

• 启动MongoDB

(py39) zhangsan@node01:/usr/local/mongodb-3.2.7$ mongod --config /mongodb/single/mongod.conf
about to fork child process, waiting until server is ready for connections.
forked process: 3493
child process started successfully, parent exiting

• 查看服务

(py39) zhangsan@node01:/usr/local/mongodb-3.2.7$ ps -ef | grep mongo
zhangsan       3493     1  3 00:56 ?        00:00:01 mongod --config /mongodb/single/mongod.conf
zhangsan       3511  3214  0 00:57 pts/0    00:00:00 grep --color=auto mongo

• 执行py程序

(py39) zhangsan@node01:~$ python3 pyinsert.py
pymongo.errors.ConfigurationError: Server at localhost:27017 reports wire version 4, but this version of PyMongo requires at least 6 (MongoDB 3.6).

很明显，此处需要降低驱动pymongo的版本

• 卸载pymongo

(py39) zhangsan@node01:~$ pip uninstall -y pymongo
Found existing installation: pymongo 4.2.0
Uninstalling pymongo-4.2.0:
  Successfully uninstalled pymongo-4.2.0
(py39) zhangsan@node01:~$ pip3 list
Package      Version
------------ ------------
certifi      2022.6.15
pip          22.1.2
setuptools   63.4.1

• 安装pymongo3.6版本

(py39) zhangsan@node01:~$ pip3 install pymongo==3.6
Collecting pymongo==3.6
  Downloading pymongo-3.6.0.tar.gz (583 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 583.3/583.3 kB 52.1 kB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
Building wheels for collected packages: pymongo
  Building wheel for pymongo (setup.py) ... done
  Created wheel for pymongo: filename=pymongo-3.6.0-cp39-cp39-linux_x86_64.whl size=272327 sha256=72a9dacdef7afa26cb169debe429964d1b5ab119ee39e7ec4c3eb5c59c5433c0
  Stored in directory: /home/zhangsan/.cache/pip/wheels/6c/97/2e/74c0fd06fe0df24ded743a8af0707d1b5d618a0e8d321ba85c
Successfully built pymongo
Installing collected packages: pymongo
Successfully installed pymongo-3.6.0
(py39) zhangsan@node01:~$ pip3 list | grep pymongo
pymongo      3.6.0

• 继续报错：AttributeError: module 'platform' has no attribute 'linux_distribution'

(py39) zhangsan@node01:~$ python3 pyinsert.py 
Traceback (most recent call last):
  File "/home/zhangsan/pyinsert.py", line 1, in <module>
    from pymongo import MongoClient 
  File "/usr/local/anaconda/envs/py39/lib/python3.9/site-packages/pymongo/__init__.py", line 87, in <module>
    from pymongo.mongo_client import MongoClient
  File "/usr/local/anaconda/envs/py39/lib/python3.9/site-packages/pymongo/mongo_client.py", line 52, in <module>
    from pymongo.client_options import ClientOptions
  File "/usr/local/anaconda/envs/py39/lib/python3.9/site-packages/pymongo/client_options.py", line 23, in <module>
    from pymongo.pool import PoolOptions
  File "/usr/local/anaconda/envs/py39/lib/python3.9/site-packages/pymongo/pool.py", line 124, in <module>
    platform.linux_distribution() if part])),
AttributeError: module 'platform' has no attribute 'linux_distribution'

关于这个error，其实是Python自身的原因

Python从3.8版本开始，已经从平台模块中删除了“linux_distribution（）”函数

前文使用的是Python3.9，解决这个问题有两种方法：

• 修改Python3.9源码
• 降低Python版本到3.7

• 新建一个Python3.7虚拟环境

zhangsan@node01:~$ conda create -n pymongo python = 3.7
zhangsan@node01:~$ conda activate pymongo
(pymongo) zhangsan@node01:~$ python3 -m pip install pymongo=3.6
Collecting pymongo
  Downloading pymongo-3.6.0-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (479 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 479.2/479.2 kB 37.7 kB/s eta 0:00:00
Installing collected packages: pymongo
Successfully installed pymongo-3.6.0

• 再次执行py程序，运行成功

(pymongo) zhangsan@node01:~$ python3 pyinsert.py

上述代码中使用了estimated_document_count()函数，该函数是MongoDB4.0.3的新功能，此处会出现错误，改为count()函数即可

2. 参考

https://stackoverflow.com/questions/63636697/error-module-platform-has-no-attribute-linux-distribution