python3: 'where' keyword

[Andrey Tatarinov]

Hi.

It would be great to be able to reverse usage/definition parts in 
haskell-way with "where" keyword. Since Python 3 would miss lambda, that 
would be extremly useful for creating readable sources.

Usage could be something like:

 >>> res = [ f(i) for i in objects ] where:
 >>>     def f(x):
 >>>         #do something

or

 >>> print words[3], words[5] where:
 >>>     words = input.split()

- defining variables in "where" block would restrict their visibility to 
one expression

- it's more easy to read sources when you know which part you can skip, 
compare to

 >>> def f(x):
 >>>     #do something
 >>> res = [ f(i) for i in objects ]

in this case you read definition of "f" before you know something about 
it usage.