爲什麼我的編程沒有正確執行？ if語句沒有被評估，它直接跳轉到Python中的else語句

Question

當我試圖向op輸入任何值時，總是執行else語句。

這裏有什麼問題？我是新來的編程

print "Basic Calculator" 
print "Options:" 
print "For addition, type add" 
print "For subtraction, type sub" 
print "For multiplication, type mul" 
print "For division, type div" 

op = raw_input() 
num1 = raw_input("Enter first number: ") 
num2 = raw_input("Enter second number: ") 

if op == 'sum': 
    print "The sum is: ", num1 + num2 
elif op == 'sub': 
    if num1 > num2: 
     print "The subtraction is: ", num1 - num2 
    else: 
     print "The subtraction is: ", num1 - num2 
elif op == 'mul': 
    print "The product is: ", num1 * num2 
elif op == 'div': 
    print "The division is: ", num1/num2 
else: 
    print "You entered an incorrect operation" 

Answer 1

這是工作的罰款，如果你輸入你想先那麼這兩個數字操作，也需要投typped爲整數的數字：

print "Basic Calculator" 
print "Options:" 
print "For addition, type add" 
print "For subtraction, type sub" 
print "For multiplication, type mul" 
print "For division, type div" 

op = raw_input("Enter the operation wanted (add, sub, mul, div): ") 
num1 = raw_input("Enter first number: ") 
num2 = raw_input("Enter second number: ") 

intNum1 = int(num1) 
intNum2 = int(num2) 
if op == 'sum': 
    print "The sum is: ", intNum1 + intNum2 
elif op == 'sub': 
    if intNum1 > intNum2: 
     print "The subtraction is: ", intNum1 - intNum2 
    else: 
     print "The subtraction is: ", intNum1 - intNum2 
elif op == 'mul': 
    print "The product is: ", intNum1 * intNum2 
elif op == 'div': 
    print "The division is: ", intNum1/intNum2 
else: 
    print "You entered an incorrect operation" 

Try it here