On Friday, April 27, 2018, Chris Angelico <rosuav@gmail.com> wrote:
On Sat, Apr 28, 2018 at 6:06 AM, Wes Turner <wes.turner@gmail.com> wrote:
On Friday, April 27, 2018, Chris Angelico <rosuav@gmail.com> wrote:
On Fri, Apr 27, 2018 at 8:18 PM, Wes Turner <wes.turner@gmail.com>
IDK, I could just be resistant to change, but this seems like something that will decrease readability -- and slow down code review -- without any real performance gain. So, while this would be useful for golfed-down (!) one-liners with pyline, I'm -1 on PEP 572.
PEP 572 has never promised a performance gain, so "without any real performance gain" is hardly a criticism.
How do I step through this simple example with a debugger?
if re.search(pat, text) as match: print("Found:", match.group(0))
Step the 'if' statement. It will call re.search() and stash the result in 'match'. Then the cursor would be put either on the 'print' (if the RE matched) or on the next executable line (if it didn't).
Right. Pdb doesn't step through the AST branches of a line, so ternary expressions and list comprehensions and defining variables at the end of
wrote: the
line are 'debugged' after they're done.
Similarly, code coverage is line-based; so those expressions may appear to be covered but are not.
I'm not sure I follow. In what situation would some code appear to be covered when it isn't, due to an assignment expression?
When an assignment expression is in the else clause of a ternary expression, but the else clause does not execute because the condition is true, the assignment expression does not execute and so isn't covered. if ((1) or (x := 3)): if ((y := func(x)) if x else (x := 3)) Is this a new opportunity for misunderstanding? Assignment expressions, though they are noticeable :=, may not actually define the variable in cases where that part of the line doesn't run but reads as covered.
ChrisA _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/ wes.turner%40gmail.com