Python 3.6.5的坑 pymysql warning

import pymysql

#鏈接數據庫 

def ConnectDB():

db = None
config={

"host":"127.0.0.1",
'port':3306,
"user":"xxxxxx",
"password":"*************",
"database":"xxxxxxx",
'charset':'utf8mb4',

}

try:

db = pymysql.connect(**config)

except Exception as e:

error = traceback.format_exc()
print("\n.... Failed to connect database:")
print(error)

if not db:

sys.exit(0)
return db

#主程序

try:

db = ConnectDB()
cursor = db.cursor()
sql = 「INSERT INTO ...」
arg = ("xxx","xxx", ...)
cursor.execute(sql, arg)
db.commit()

except Exception as e:

error = traceback.format_exc()
print(error)
db.rollback()

"""
#--------------------------------------
#若是這個時候出現錯誤：
C:\Program Files\Python36\lib\site-packages\pymysql\cursors.py:167: Warning: (1300, "Invalid utf8mb4 character string: 'C191D4'")
result = self._query(query)
#這個錯誤Exception捕捉不到，"Warning: (1300, ..." 對INSERT結果幾乎沒有影響，要插入的內容還會保存到數據庫裏，MySQL沒有db.rollback()

#若是要捕捉pymysql， 要用到這個庫：
from warnings import filterwarnings
filterwarnings("error",category=pymysql.Warning)
#而後「except Exception as e:「變成
except pymysql.Warning as e:
print(e)
#可是坑在這裏了，一旦出現pymysql.Warning， 就會觸發db.rollback()，數據不會被保存！！
#--------------------------------------
"""

from warnings import filterwarnings
filterwarnings("error",category=pymysql.Warning)

 #主程序：

try:

db = ConnectDB()
cursor = db.cursor()
sql = 「INSERT INTO ...」
arg = ("xxx","xxx", ...)
cursor.execute(sql, arg)
db.commit()

except pymysql.Warning as e:

error = traceback.format_exc()
print(error)

#db.rollback() 這裏不用寫db.rollback()， 多是這模塊warnings的filterwarnings默認就是要這樣作的

#Python 3.6.5 (v3.6.5:f59c0932b4, Mar 28 2018, 17:00:18) [MSC v.1900 64 bit (AMD64)] on win32

#pymysql 0.9.2