On 3/21/2020 1:19 PM, duncan smith wrote:
Hello,
I have a class I wrote for Python2 that needs to be made to work
on Python3. On Python2 it inherited from long, so it needs to inherit
from int on Python3.
In general, if you want code to work on both 2 and 3, look into the
bi-version packages such as 'six' and 'future' and documents such as
https://python-future.org/compatible_idioms.html.
If 'long' appears more than once in your code, you might prefer using
this at the top.
if sys.version_info.major >= 3:
long = int
This has the plus of indicating that this is a 2 and 3 file, if anyone
else reads it.
The following works, but I'm not sure it's the cleanest solution.
It does not bother me.
It's the first time I've wanted / needed to make a
parent class conditional on the Python version, and I'm not sure it's
even a good idea. I used inheritance because I wanted to perform bitwise
operations on instances, but I could probably switch to composition.
Just wondering how bad the following really is (in a code smell kind of
a away). TIA.
import sys
class C_hash(int if sys.version_info.major >= 3 else long):
def __new__(cls, bits, m, N=1):
obj = super(C_hash, cls).__new__(cls, bits)
obj._m = m
obj._N = N
return obj
--
Terry Jan Reedy
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