+ 13
Explain how you reverse a generator?
I confused because its not reversed(), but how?
6 ответов
+ 17
You cannot reverse a generator in any generic way except by casting it to a sequence and creating an iterator from that. Later terms of a generator cannot necessarily be known until the earlier ones have been calculated.
Even worse, you can’t know if your generator will ever hit a StopIteration exception until you hit it, so there’s no way to know what there will even be a first term in your sequence.
The best you could do would be to write a reversed_iterator function:
def reversed_iterator(iter):
return reversed(list(iter))
You could also, of course, replace reversed in this with your imap based iterative version, to save one list creation.
+ 10
def reversed_iterator(iter):
return reversed(list(iter))
+ 8
Is this the sort of thing you mean:-
def rev_gen():
for x in range(100, 0, -1):
yield x
for x in rev_gen():
print(x)
+ 8
Use imap is what I'd do.
+ 5
Don't spam Guna please!
- 1
ghj