[Python-bugs-list] [ python-Bugs-585915 ] assert return values

[noreply@sourceforge.net]

Bugs item #585915, was opened at 2002-07-24 13:28
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=585915&group_id=5470

Category: Python Interpreter Core
Group: Feature Request
>Status: Closed
Resolution: None
Priority: 5
Submitted By: Thomas Leonard (tal197)
Assigned to: Nobody/Anonymous (nobody)
Summary: assert return values

Initial Comment:
It would be nice to write:

def root(x):
  assert x >= 0
  assert return >= 0
  ...

or

def get_path(foo):
  if foo is None: return None
  assert return is not None
  ...

and have the 'return' assertion checked when the function
exits. 'return' is already a reserved keyword so the
syntax doesn't introduce any incompatibility.

This might make functions more self-documenting, since
asserts at the end / in the middle tend to get lost.

Even if the assert goes at the end, it's still clearer, eg:

def foo():
  ...
  assert min <= return <= max
  return bar(min, max)

vs

def foo():
  ...
  tmp = bar(min, max)
  assert min <= tmp <= max
  return tmp

Thanks!


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>Comment By: Jeremy Hylton (jhylton)
Date: 2002-07-24 15:06

Message:
Logged In: YES 
user_id=31392

I don't think this is a great feature.  It seems like
control flow via yield or return  could easily be overlooked
if it's inside an assert statement.

Regardless of whether I like the idea, the SF bug tracker
isn't the right place to make this suggestion.  The right
thing to do is write a PEP describing the feature in detail,
then come up with a patch to implement it.  If that's too
much work, but you really like the idea, you could try to
drum up interest on comp.lang.python.


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You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=585915&group_id=5470