Home/ Questions/Q 8245605
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-07T22:14:05+00:00

I am trying to write a small Python 2.x API to support fetching a

  • 0

I am trying to write a small Python 2.x API to support fetching a
job by jobNumber, where jobNumber is provided as an integer.
Sometimes the users provide ajobNumber as an integer literal
beginning with 0, e.g. 037537. (This is because they have been
coddled by R, a language that sanely considers 037537==37537.)
Python, however, considers integer literals starting with “0” to
be OCTAL, thus 037537!=37537, instead 037537==16223. This
strikes me as a blatant affront to the principle of least
surprise, and thankfully it looks like this was fixed in Python
3—see PEP 3127.

But I’m stuck with Python 2.7 at the moment. So my users do this:

>>> fetchJob(037537)

and silently get the wrong job (16223), or this:

>>> fetchJob(038537)
File "<stdin>", line 1
 fetchJob(038537)
            ^
SyntaxError: invalid token

where Python is rejecting the octal-incompatible digit.

There doesn’t seem to be anything provided via __future__ to
allow me to get the Py3K behavior—it would have to be built-in
to Python in some manner, since it requires a change to the lexer
at least.

Is anyone aware of how I could protect my users from getting the
wrong job in cases like this? At the moment the best I can think
of is to change that API so it take a string instead of an int.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    At the moment the best I can think of is to change that API so it take a string instead of an int.

    Yes, and I think this is a reasonable option given the situation.

    Another option would be to make sure that all your job numbers contain at least one digit greater than 7 so that adding the leading zero will give an error immediately instead of an incorrect result, but that seems like a bigger hack than using strings.

    A final option could be to educate your users. It will only take five minutes or so to explain not to add the leading zero and what can happen if you do. Even if they forget or accidentally add the zero due to old habits, they are more likely to spot the problem if they have heard of it before.

    • 0