我还是一个编程新手，我想用python做一个简单的计算器。然而，我只能到达我的代码的这一点:
import operator as op
print("Greetings user, welcome to the calculator program.nWe offer a list of functions:")
print("1. Addn2. Subtractn3. Multiplyn4. Dividen5. Modulusn6. Check greater number")
while True:
userInput = input("Please choose what function you would like to use based on their numbers:")
if userInput.isdigit():
if int(userInput) in range(1,7):
str(userInput)
break
else:
print("Number inputted is either below or above the given choices")
continue
else:
print("Incorrect input. Please try again.")
continue
def add(x,y):
return op.add(x,y)
def sub(x,y):
return op.sub(x,y)
def mul(x,y):
return op.mul(x,y)
def div(x,y):
return op.truediv(x,y)
def mod(x,y):
return op.mod(x,y)
def gt(x,y):
if x == y:
return "Equal"
else:
return op.gt(x,y)
variableA = 0
variableB = 0
while True:
variableA = input("Enter the first value: ")
if variableA.isdigit():
float(variableA)
break
else:
print("Incorrect input. Please try again.")
continue
while True:
variableB = input("Enter the second value: ")
if variableB.isdigit():
float(variableB)
break
else:
print("Incorrect input. Please try again.")
continue
if userInput == 1:
print("You chose to add the two numbers and the result is:")
print(add(variableA,variableB))
print("Thank you")
elif userInput == 2:
print("You chose to subtract with the two numbers and the result is:")
print(sub(variableA,variableB))
print("Thank you")
elif userInput == 3:
print("You chose to multiply the two numbers and the result is:")
print(mul(variableA,variableB))
print("Thank you")
elif userInput == 4:
print("You chose to divide with the two numbers and the result is:")
print(div(variableA,variableB))
print("Thank you")
elif userInput == 5:
print("You chose to find the modulo with the two numbers and the result is:")
print(mod(variableA,variableB))
print("Thank you")
elif userInput == 6:
print("Is the first input greater than the second?")
if sub(variableA,variableB) == True:
print(f"{sub(variableA,variableB)}. {variableA} is greater than {variableB}")
elif sub(variableA,variableB) == False:
print(f"{sub(variableA,variableB)}. {variableB} is greater than {variableA}")
else:
print(f"It is {sub(variableA,variableB)}")
print("Thank you")
不知道为什么我的if语句在用户输入所有正确的输入后没有执行。我主要关注错误处理部分，在一切顺利之后，if语句只是没有执行。这可能是一个简单的错误，但即使是我也不明白这里发生了什么。
类型转换有问题。所以当你从用户那里得到输入的时候，所有的userInput都是str而不是int，所以在做进一步的计算器运算之前，你需要把它像userInput = int(userInput)一样进行转换。此外，您需要将float类型转换分配给像variableA = float(variableA)和variableB = float(variableB)这样的变量，否则您的加/减/除/乘等将无法执行预期的操作。
例如add将做串联，即'2' + '4' = 24不是2 + 4 =6.0
import operator as op
print("Greetings user, welcome to the calculator program.nWe offer a list of functions:")
print("1. Addn2. Subtractn3. Multiplyn4. Dividen5. Modulusn6. Check greater number")
while True:
userInput = input("Please choose what function you would like to use based on their numbers:")
if userInput.isdigit():
if int(userInput) in range(1,7):
str(userInput)
break
else:
print("Number inputted is either below or above the given choices")
continue
else:
print("Incorrect input. Please try again.")
continue
def add(x,y):
return op.add(x,y)
def sub(x,y):
return op.sub(x,y)
def mul(x,y):
return op.mul(x,y)
def div(x,y):
return op.truediv(x,y)
def mod(x,y):
return op.mod(x,y)
def gt(x,y):
if x == y:
return "Equal"
else:
return op.gt(x,y)
variableA = 0
variableB = 0
while True:
variableA = input("Enter the first value: ")
if variableA.isdigit():
variableA = float(variableA) # <-- fix this line
break
else:
print("Incorrect input. Please try again.")
continue
while True:
variableB = input("Enter the second value: ")
if variableB.isdigit():
variableB = float(variableB) # <-- fix this line
break
else:
print("Incorrect input. Please try again.")
continue
userInput = int(userInput) # <-- fix this line
if userInput == 1:
print("You chose to add the two numbers and the result is:")
print(add(variableA,variableB))
print("Thank you")
elif userInput == 2:
print("You chose to subtract with the two numbers and the result is:")
print(sub(variableA,variableB))
print("Thank you")
elif userInput == 3:
print("You chose to multiply the two numbers and the result is:")
print(mul(variableA,variableB))
print("Thank you")
elif userInput == 4:
print("You chose to divide with the two numbers and the result is:")
print(div(variableA,variableB))
print("Thank you")
elif userInput == 5:
print("You chose to find the modulo with the two numbers and the result is:")
print(mod(variableA,variableB))
print("Thank you")
elif userInput == 6:
print("Is the first input greater than the second?")
if sub(variableA,variableB) == True:
print(f"{sub(variableA,variableB)}. {variableA} is greater than {variableB}")
elif sub(variableA,variableB) == False:
print(f"{sub(variableA,variableB)}. {variableB} is greater than {variableA}")
else:
print(f"It is {sub(variableA,variableB)}")
print("Thank you")
如果用户输入应该是int，尽早转换，快速失败。
while True:
userInput = input(...)
try:
userInput = int(userInput)
except ValueError:
print("Not an integer, try again")
continue
if userInput in range(1, 7):
break
print("Number out of range, try again")
和类似的
操作数while True:
variableA = input("Enter the first value: ")
try:
variableA = float(variableA)
break
except ValueError:
print("not a float")
while True:
userInput = input(...)
if userInput in "123456": # ... in ["1", "2", "3", "4", "5", "6"]
break
print("Invalid choice, try again")