On 12/16/2012 11:19 PM, boB Stepp wrote:
int('10.0')
> Traceback (most recent call last):
> File "<interactive input>", line 1, in <module>
> ValueError: invalid literal for int() with base 10: '10.0'
>>>> int("10")
> 10
>
> It is apparent that int() does not like strings with floating-point
> formats. None of my books (as far as my flipping can tell) or the
> below built-in help clarify this:
>
>
> Help on int object:
>
> class int(object)
> | int(x[, base]) -> integer
> |
> | Convert a string or number to an integer, if possible. A floating
> | point argument will be truncated towards zero (this does not include a
> | string representation of a floating point number!) When converting a
> | string, use the optional base. It is an error to supply a base when
> | converting a non-string.
>
> Of course if I type int(float('10.0')) I get the desired 10 .
>
> So, I am guessing that to convert strings to integers with int() that
> the string must already be of integer format? What is the rationale
> for setting up int() in this manner?
>
> Thanks as I continue to puzzle over the fine points of the basics...
> boB
What would you want to happen for int("10.5")? If 10.0 was accepted,
it would be consistent to accept 10.5, too.
The issue, I think, is that a simple operation should not go too far
beyond what it is supposed to do - if you are sure you are converting a
float in a string, you need to do it explicitly, and if you're
converting a string to an int and the string is not actually an int,
then maybe it wasn't supposed to be a float and it's a mistake in the
program -- and therefore python should alert you.
--
Lark's Tongue Guide to Python: http://lightbird.net/larks/
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