Problems using struct pack/unpack in files, and reading them.

[Steven D'Aprano]

On Sun, 15 Nov 2015 01:23 pm, Chris Angelico wrote:

> On Sun, Nov 15, 2015 at 1:08 PM, Steven D'Aprano <steve at pearwood.info>
> wrote:
>> number = +raw_input("enter a number: ")
>>
>> versus:
>>
>> text = raw_input("enter a number: ")
>> try:
>>     number = float(text)
>> except ValueError:
>>     number = int(text)
> 
> What kinds of strings can float() not handle but int() can, 

Heh, I think I got the order of them backwards. You should try to convert to
int first, and if that fails, try float.


> and in a 
> program that's going to group floats and ints together as "numbers",
> will they ever be useful? I'd be more likely to write this as simply:

Obviously this code assumes you want to distinguish between ints and floats
for some reason. In Python, unlike Lua, Javascript and a few others, we do
distinguish between ints and floats. Since they have different
capabilities, that may sometimes be useful:


py> 10.0 ** 400
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: (34, 'Numerical result out of range')
py> 10 ** 400
1000000000000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000


-- 
Steven