> I guess that's inevitable (given lambda's existence... and human
> nature;-) and about on the same plane as another hatefully redundant
> construct I find myself having to beat upon over and over in code
> reviews:
>
> if <expression>:
> result = True
> else:
> result = False
> return result
>
> vs the simple "return <expression>" [[or bool(<expression>) if it's
> actually mandatory to return a bool and <expression> can't be relied
> upon to produce one]].
Indeed, I think these are the same phenomenons. If lambdas where not
available, people would, instead of writing
Thread(target = lambda: foo())
write
def target():
foo()
Thread(target = target)
Your example above demonstrates that the boolean type is a concept that
is *very* difficult to grasp (not the notion of boolean expressions,
which are easy to understand - it's the boolean *type* that is
difficult, i.e. that a boolean expression can be used not just in
conditional statements, but also assigned to variables, returned, etc.).
When I ask students in the exam to rewrite your code above (and assuming
they use Java), so that "it is a single line", they typically write
return <expression> ? true : false;
Likewise, apparently, the notion of generic callables is difficult
to understand. Unless you have written it yourself, you won't recognize
an expression as callable.
Regards,
Martin
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
http://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
