我是编程新手，我正努力使我的代码循环回到起点，以便用户可以选择其他操作，而不必重新启动程序。我知道显而易见的答案是添加一个while循环，但是我在实现此策略时遇到了麻烦。我试图寻求帮助，以了解这样做的最佳方法。谢谢。
print('Python Calculator Program')
print(' MENU')
print('1)Add')
print('2)Subtract')
print('3)Multiply')
print('4)Divide')
print('5)Square Root')
print('6)Exit')
print('Enter Your Choice:')
operator=input('Choose a number 1 - 6: ')
while True:
if operator == '1' or operator == 'Add' or operator == 'add':
a=float(input('Enter the fist number that you wish to add: '))
b=float(input('Enter the second number that you wish to add: '))
ans=sum(a,b)
print('The sum of the numbers are: ', ans)
elif operator == '2' or operator == 'Subtract' or operator == 'subtract':
a=float(input('Enter the fist number that you wish to subtract: '))
b=float(input('Enter the second number that you wish to subtract: '))
ans=difference(a,b)
print('The difference of the numbers are: ', ans)
elif operator == '3' or operator == 'Multiply' or operator == 'multiply':
a=float(input('Enter the fist number that you wish to multiply: '))
b=float(input('Enter the second number that you wish to multiply: '))
ans=product(a,b)
print('The product of the numbers are: ', ans)
elif operator == '4' or operator == 'Divide' or operator == 'divide':
a=float(input('Enter the dividend: '))
b=float(input('Enter the divisor: '))
ans=quotient(a,b)
print('The quotient of the numbers are: ', ans)
elif operator == '5' or operator == 'Square Root' or operator == 'sqaure root':
a=float(input('Enter the number you wish to find the square root of: '))
ans=sqrt(a)
print('The square root of the number is: ', ans)
elif operator =='6':
print('CALCULATOR: ON [OFF]')
break
else:
print('Enter the math operator as dislayed')
operator=input('Choose an operator: ')
def sum(a,b):
return a+b
def difference(a,b):
return a-b
def product(a,b):
return a*b
def quotient(a,b):
return a/b
def sqrt(a):
import math
return(math.sqrt(a))
main()
答案 0 :(得分：1)
我认为您的帖子中的代码缩进不可用，但我想您只是想让用户输入每个循环，在这种情况下，您可以简单地移动代码行
while True:
operator=input('Choose a number 1 - 6: ')
if operator == '1' or operator == 'Add' or operator == 'add':
..... # all your other code
答案 1 :(得分：1)
要回答您的原始问题，每次程序循环时都必须重新提示，因此您需要将提示放入循环中。我知道您说您是编码的新手，所以我花了一些时间遍历您的代码并修正/注释了一些内容，希望可以帮助您更高效地完成工作
import math
def sum(a,b): return a+b
def difference(a,b): return a-b
def product(a,b): return a*b
def quotient(a,b): return a/b
def sqrt(a): return(math.sqrt(a))
def selectMenu():
print('Python Calculator Program')
print(' MENU')
print('1)Add')
print('2)Subtract')
print('3)Multiply')
print('4)Divide')
print('5)Square Root')
print('6)Exit')
print('Enter Your Choice:')
return input('Choose a number 1 - 6: ')
def main():
ans = "" #declare ans because if we try to see if ans == "" and ans doesnt exist, the
#program will crash
operator = "" # "" is not 6, therefore the while loop will run at least once
while operator != '6': #as long as the variable operator is not 6 // operator != '6'
#is your condition
operator = selectMenu() #this will get the user's choice
operation = "" #our placeholder for the operation string
if operator == '1' or operator.lower() == 'add': #.lower() will convert the
#entire string to lowercase, so
#that you dont have to test for
#caps
a=float(input('Enter the fist number that you wish to add: '))
b=float(input('Enter the second number that you wish to add: '))
operation = "sum"
ans= sum(a,b)
elif operator == '2' or operator.lower() == 'subtract':
a=float(input('Enter the fist number that you wish to subtract: '))
b=float(input('Enter the second number that you wish to subtract: '))
operation = "difference"
ans = difference(a, b)
elif operator == '3' or operator.lower() == 'multiply':
a=float(input('Enter the fist number that you wish to multiply: '))
b=float(input('Enter the second number that you wish to multiply: '))
operation = "product"
ans=product(a,b)
elif operator == '4' or operator.lower() == 'divide':
a=float(input('Enter the dividend: '))
b=float(input('Enter the divisor: '))
operation = "quotient"
ans=quotient(a,b)
elif operator == '5' or operator.lower() == 'square root':
a=float(input('Enter the number you wish to find the square root of: '))
operation = "square root"
ans=sqrt(a)
elif operator =='6':
print('CALCULATOR: ON [OFF]')
operation = ""
ans = ""
#break // while break technically works, its a bad habit to get in to. your
#loops should naturally terminate themselves by causing the condition to
#become false
else:
print('Enter the math operator as displayed')
if ans != "": # since we're always gonna print the answer no matter what
#they pick, its easier to do it after your if statements.
print() #print empty lines for spacing
print("The ", operation, " is: ", ans)
print()
main()
答案 2 :(得分：0)
我有一个非常类似于您所需的代码。 请注意，您没有检查用户的有效输入。
希望有帮助
import math
def isfloat(value):
"""
Checks if the given value represent float
:param value:
:return: True if float
"""
try:
float(value)
return True
except:
return False
def chooseOperator(input):
# Returns a method to run
return {
'1': oneAdd,
'add': oneAdd,
'2': twoDif,
'subtract': twoDif,
'3': threeMult,
'multiply': threeMult,
'4': fourDiv,
'divide': fourDiv,
'5': fiveSqrt,
'sqaure root': fiveSqrt,
'6': sixExit,
'exit': sixExit
}[input]
def printMenu():
print('\n\t-- MENU --')
print('1)\t Add')
print('2)\t Subtract')
print('3)\t Multiply')
print('4)\t Divide')
print('5)\t Square Root')
print('6)\t Exit')
def mainLoop():
inputFromUser = True
print('\n\n** Python Calculator Program **')
print('CALCULATOR: [ON] OFF')
while inputFromUser:
# Prints the menu to the console
printMenu()
try:
# operator is a function
operator = chooseOperator((input('Choose an operator: ')).lower())
# inputFromUser is a boolean variable
inputFromUser = operator()
except KeyError:
# Unknown input
print('\n\t Please choose an operator from the menu')
def oneAdd():
# Get input from user
a = input('Enter the first number that you wish to add: ')
b = input('Enter the second number that you wish to add: ')
# Check that the input is valid
if isfloat(a) and isfloat(b):
# Calculate with values
ans = float(a) + float(b)
print('The sum of the numbers are: ', ans)
else:
# Notify the user that the values are not valid
print("\tInvalid values:")
print("\t\tfirst = ", a)
print("\t\tsecond = ", b)
return True
def twoDif():
# Get input from user
a = input('Enter the first number that you wish to subtract: ')
b = input('Enter the second number that you wish to subtract: ')
# Check that the input is valid
if isfloat(a) and isfloat(b):
# Calculate with values
ans = float(a) - float(b)
print('The difference of the numbers are: ', ans)
else:
# Notify the user that the values are not valid
print("\tInvalid values:")
print("\t\tfirst = ", a)
print("\t\tsecond = ", b)
return True
def threeMult():
# Get input from user
a = input('Enter the first number that you wish to multiply: ')
b = input('Enter the second number that you wish to multiply: ')
# Check that the input is valid
if isfloat(a) and isfloat(b):
# Calculate with values
ans = float(a) * float(b)
print('The product of the numbers are: ', ans)
else:
# Notify the user that the values are not valid
print("\tInvalid values:")
print("\t\tfirst = ", a)
print("\t\tsecond = ", b)
return True
def fourDiv():
# Get input from user
a = input('Enter the dividend: ')
b = input('Enter the divisor: ')
# Check that the input is valid
if isfloat(a) and isfloat(b):
# Calculate with values
ans = float(a) / float(b)
print('The quotient of the numbers are: ', ans)
else:
# Notify the user that the values are not valid
print("\tInvalid values:")
print("\t\tfirst = ", a)
print("\t\tsecond = ", b)
return True
def fiveSqrt():
# Get input from user
a = input('Enter the number you wish to find the square root of: ')
# Check that the input is valid
if isfloat(a):
# Calculate with values
ans = math.sqrt(float(a))
print('The square root of the number is: ', ans)
else:
# Notify the user that the values are not valid
print("\tInvalid value:")
print("\t\tfirst = ", a)
return True
def sixExit():
print('\n\nCALCULATOR: ON [OFF]')
return False
if __name__ == '__main__':
mainLoop()