[Tutor] Additional help

Prasad, Ramit ramit.prasad at jpmorgan.com
Wed Feb 13 21:17:02 CET 2013


Ahmet Can KEPENEK wrote:
> Hello,
> I used regular expression module of python. I checked binary and denary numbers. If input is invalid i
> ask again. I edited your code. Code is below follow as .
> 
[snip]
>         if re.match("^[0-1]*$", binary):
>         if re.match("^[0-9]*$", denary2):
[snip]

Both of these will fail for empty strings (or '\n'). 

I will quote Steven D'Aprano's often quoted quotation regarding
regular expressions. (Say that 5 times fast :) )


'''
Some people, when confronted with a problem, think "I know,
     I'll use regular expressions." Now they have two problems.
     -- Jamie Zawinski
'''

I think it would be more accurate (and easier) to convert to 
int and see if the conversion works.

int(binary, 2) # binary = base 2
int(denary2, 10) # denary = base 10


~Ramit


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