Python comparison incorrect with large integers

Question

Just starting to learn a bit of python, and for some reason, my script I just put together returns that a number such as 10000000000000000 < 5. I assume this is due to native inaccuracy with the int type at large values, but I'm not sure, perhaps I'm just doing something wrong!

Here's my (poorly written, I know) script:

def checkValue(n):
    while True:
        if n == '':
            print 'You didn\'t enter anything!'
            return False
        else:
            try:
                n = int(n)
            except ValueError:
                print 'That is not an integer!'
                return False
            else:
                break

    return True

while True:
    firstNum = raw_input('Enter the first number: ')
    if checkValue(firstNum) == False:
        continue
    else:
        break
while True:
    secNum = raw_input('Enter the second number: ')
    if checkValue(secNum) == False:
        continue
    else:
        break
while True:
    thirdNum = raw_input('Enter the third number: ')
    if checkValue(thirdNum) == False:
        continue
    else:
        break

if thirdNum > secNum and thirdNum > firstNum:
    print 'The third number is the biggest.'
elif secNum > firstNum:
    print 'The second number is the biggest.'
else:
    print 'The first number is the biggest.'

Answer 1

In your " checkValue " function you are converting the inputs in to " int ". But at the comparison you use entered string values. So you can convert "firstNum", "secNum" and "thirdNum" at the input stage. See the difference.

In [2]: firstNum = raw_input('Enter the first number: ')

In [3]: firstNum
Out[3]: '5'

In [4]: int_first = int(firstNum)

In [5]: int_first
Out[5]: 5

Answer 2

您需要使用intfirstNum = int(firstNum)将原始输入， firstNum等转换为整数。