Python--异常处理

# import traceback
# import pymysql


# def calc(a, b):
#     res = (a / b)
#     return res
#
#
# def main():
#     money = input(‘输入多少钱：‘)
#     months = input(‘还几个月：‘)
#     try:
#         res = calc(int(money), int(months))
#     except ZeroDivisionError as e:  # try里面的代码出错了，走excel里面的代码
#         traceback.print_exc()  # 只是输出报错的详细信息
#         print(‘还款的月数不能小于1‘, e)
#     except ValueError as e:
#         print(‘输入必须是整数‘, e)
#     except Exception as e:  # 捕获所有的异常
#         print(‘未知错误！‘, e)
#     else:  # try里面的代码没有出错，走else
#         print(‘每个月应该还%s‘ % res)
#     print(‘hahahaha‘)
#
#
# def main2():
#     try:
#         conn = pymysql.connect(host=‘122.932.122.11‘, user=‘root‘, password=‘123456‘, db=‘test‘)
#     except Exception as e:
#         print(‘数据库连接不了‘, e)
#     else:
#         cur = conn.cursor()
#         sql = ‘select * from a;‘
#         try:
#             cur.execute(sql)
#         except Exception as e:
#             print(‘sql语句有错误！%s，sql是%s‘ % (e, sql))
#         else:
#             res = cur.fetchall()
#             return res
#         finally:  # 不管有没有捕捉到异常，都会走这里
#             cur.close()
#             conn.close()


# try:
#     a = int(input(‘输入：‘))
#     b = int(input(‘输入：‘))
#     res = a / b
# except Exception as e:
#     print(e)
# else:
#     print(res)
# finally:
#     print(‘什么时候到我这里呢‘)

import requests


def req():
    r = requests.get(‘http://api.nnzhp.cn/api/user/all_stu‘, headers={‘Referer‘: ‘http://api.nnzhp.cn/‘})
    if len(r.json()[‘stu_info‘]) < 0:
        pass
    else:
        raise Exception(‘主动抛出异常!‘)  # 主动抛出异常
    print(‘hahahaha‘)


req()