我在这里制作一个小型计算器。接受两个数字和一个运算符这将是很容易，而我正在使用函数，但在这我使用while条件语句，但有一个错误，它不会打破，而每次操作它会要求用户，它会想要任何在'Y'中再次操作是，而'N'再次操作，但是有一个错误，它不会改变n的值。以下是我的计划：
n = 1
def again(number):
print('value of n in again fucntion', n)
calc_again = input('''
Do you want to calculate again?
Please type Y for YES or N for NO.
''')
if calc_again.upper() == 'Y':
number = 1
return number
elif calc_again.upper() == 'N':
number = 0
print('value of n after say no', number)
return number
else:
again(n)
while n > 0:
print('while n value', n)
operation = input('''
Please type in the math operation you would like to complete:
+ for addition
- for subtraction
* for multiplication
/ for division
''')
number_1 = int(input('Please enter the first number: '))
number_2 = int(input('Please enter the second number: '))
if operation == '+':
print('{} + {} = '.format(number_1, number_2))
print(number_1 + number_2)
again(n)
elif operation == '-':
print('{} - {} = '.format(number_1, number_2))
print(number_1 - number_2)
again(n)
elif operation == '*':
print('{} * {} = '.format(number_1, number_2))
print(number_1 * number_2)
again(n)
elif operation == '/':
print('{} / {} = '.format(number_1, number_2))
print(number_1 / number_2)
again(n)
else:
print('You have not typed a valid operator, please run the program again.')
任何人都可以帮我解决这个问题。提前致谢。
你在number中使用局部变量again，但在外面使用n。您必须将again的返回值分配给n。
def again():
while True:
calc_again = input('''
Do you want to calculate again?
Please type Y for YES or N for NO.
''')
if calc_again.upper() == 'Y':
number = 1
return number
elif calc_again.upper() == 'N':
number = 0
print('value of n after say no', number)
return number
n = 1
while n > 0:
print('while n value', n)
operation = input('''
Please type in the math operation you would like to complete:
+ for addition
- for subtraction
* for multiplication
/ for division
''')
number_1 = int(input('Please enter the first number: '))
number_2 = int(input('Please enter the second number: '))
if operation == '+':
print('{} + {} = '.format(number_1, number_2))
print(number_1 + number_2)
elif operation == '-':
print('{} - {} = '.format(number_1, number_2))
print(number_1 - number_2)
elif operation == '*':
print('{} * {} = '.format(number_1, number_2))
print(number_1 * number_2)
elif operation == '/':
print('{} / {} = '.format(number_1, number_2))
print(number_1 / number_2)
else:
print('You have not typed a valid operator, please run the program again.')
n = again()
如果你想打破你的循环，那么只需使用break，你想要循环停止。
编辑： 你的循环可以像：
while n > 0:
print('while n value', n)
operation = input('''
Please type in the math operation you would like to complete:
+ for addition
- for subtraction
* for multiplication
/ for division
''')
number_1 = int(input('Please enter the first number: '))
number_2 = int(input('Please enter the second number: '))
if operation == '+':
print('{} + {} = '.format(number_1, number_2))
print(number_1 + number_2)
if again(n) == 0:break
elif operation == '-':
print('{} - {} = '.format(number_1, number_2))
print(number_1 - number_2)
if again(n) == 0:break
elif operation == '*':
print('{} * {} = '.format(number_1, number_2))
print(number_1 * number_2)
if again(n) == 0:break
elif operation == '/':
print('{} / {} = '.format(number_1, number_2))
print(number_1 / number_2)
if again(n) == 0:break
else:
print('You have not typed a valid operator, please run the program again.')
没有必要存储值n
while循环更改为while True:again函数以返回布尔值。again函数时使用以下语法。
if not again():
break
没有必要存储值n
while循环更改为while True:again函数以返回布尔值。again函数时使用以下语法。
if not again():
break
最终的代码将是这样的。
def again():
calc_again = input('''
Do you want to calculate again?
Please type Y for YES or N for NO.
''')
if calc_again.upper() == 'Y':
return True
elif calc_again.upper() == 'N':
return False
else:
return again()
while True:
operation = input('''
Please type in the math operation you would like to complete:
+ for addition
- for subtraction
* for multiplication
/ for division
''')
number_1 = int(input('Please enter the first number: '))
number_2 = int(input('Please enter the second number: '))
if operation == '+':
print('{} + {} = '.format(number_1, number_2))
print(number_1 + number_2)
elif operation == '-':
print('{} - {} = '.format(number_1, number_2))
print(number_1 - number_2)
elif operation == '*':
print('{} * {} = '.format(number_1, number_2))
print(number_1 * number_2)
elif operation == '/':
print('{} / {} = '.format(number_1, number_2))
print(number_1 / number_2)
else:
print('You have not typed a valid operator, please run the program again.')
break
if not again():
break
您可以按照以下方式简化代码，并避免代码中不必要的递归：
operations = {
"+": lambda x, y: x + y,
"-": lambda x, y: x - y,
"/": lambda x, y: x / y,
"*": lambda x, y: x * y
}
continue_calculation = ""
while True:
calc_again = input('''Do you want to calculate again?Please type Y for YES or N for NO.''')
if calc_again == "n" or calc_again == "N":
break
operation = input('''Please type in the math operation you would like to complete:
+ for addition
- for subtraction
* for multiplication
/ for division
''')
number_1 = int(input('Please enter the first number: '))
number_2 = int(input('Please enter the second number: '))
try:
print(operations[operation](number_1, number_2))
except:
print('You have not typed a valid operator, please run the program again.')