[Python-ideas] Add "while" clauses to generator expressions

[Mathias Panzenböck]

Gerald Britton schrieb:
> I've been using Python generators for a while now.  e.g.
> 
> a=(i for i in range(10))
> 
> a.next()
> a.next()
> ...etc.
> 
> I also find the "if" clause handy:
> 
> a = (i for i in range(10) if i%2==0)
> 
> (I know that range(0,12,2) will do the same thing, but it's the idea I
> like, especially for more complex predicates.)
> 
> I would like to know if anyone has thought of adding a "while" clause
> as well, like this:
> 
> a = (i for i in range(100) while i <=50)
> 

from itertools takewhile
a = takewhile(lambda i: i <= 50, xrange(100))