Re: [Python-Dev] 2.5 and beyond

July 1, 2006


      Tim Peters <tim.peters@gmail.com> wrote:
...
...
...
Incidentally, I think that lexical scoping would also deal with the
problem
that people often encounter in which they have to write things like
"lambda
x=x:" where one would think "lambda x:" would suffice.
They _shouldn't_ encounter that at all anymore.  For example,
...
...
...
def f(x):
...     return lambda: x+1
f(3)()
4
works fine in modern Pythons.
Yes but:
...
...
...
a = []
for i in range(10):
...     a.append(lambda: i)
...
print [x() for x in a]
[9, 9, 9, 9, 9, 9, 9, 9, 9, 9]
This subtle semantic of lambda is quite confusing, and still forces people to
use the "i=i" trick.

Giovanni Bajo