while True:
try:
op = input('请输入一个四则运算格式（例如1 + 2）')
if '+' in op: #'加法':
a = op.split('+')
result = int(a[0]) + int(a[1])
print(result)
elif '-' in op:
a = op.split('-')
result = int(a[0]) - int(a[1])
print(result)
elif '' in op:
a = op.split('')
result = int(a[0]) * int(a[1])
print(result)
elif '/' in op:
a = op.split('/')
result = int(a[0]) / int(a[1])
print(result)
elif op == 'c':
print('感谢您使用本计算器')
break
else:
raise Exception('请按1+2这个格式输入算式')
except ZeroDivisionError:
print('注意除法运算，除数不能为0')
except Exception as e:
print(e)