from pymysql import connect

class DB(object):
def __init__(self, password, database):
# 1.连接数据库
self.conn = connect(host='localhost', port=3306, user='root', password=str(password), database=str(database),
charset='utf8')
# 2.创建游标
self.cs = self.conn.cursor()

def __enter__(self):
return self.cs

def __exit__(self, exc_type, exc_val, exc_tb):
# 3.关闭
self.cs.close()
self.conn.close()

# 利用上下文管理器来封装的数据库的操作，只需要传入密码和需要连接的数据库就可以了
with DB("mysql", "student_selection") as db:
# 需要执行的数据库操作（sql语句）
db.execute("select * from student; ")
# 循环取出查找的数据
data = db.fetchall()
for content in data:
print(content)