How to find the length of an iterator?

[Thorsten Kampe]

What is the best way to find out the length of an iterator? len()
doesn't work. In the above code snippet[1] I am only interested in the
index (= length of the iterator), so I'm using len(list(iterator))...

Anything better?

Thanks, Thorsten

[2]
def part(seq, func):
from itertools import takewhile
index = len(list(takewhile(func, seq)))
return [seq[:index], seq[index:]]

 

[Diez B. Roggisch]

What is the best way to find out the length of an iterator? len()
doesn't work. In the above code snippet[1] I am only interested in the
index (= length of the iterator), so I'm using len(list(iterator))...

Anything better?

Its the nature of an iterator that it doesn't support anything beyond access
to the current item and signaling when its finished. So if you need the
length, try to get a hold on the underlying connection.

 

[Diez B. Roggisch]

Its the nature of an iterator that it doesn't support anything beyond
access to the current item and signaling when its finished. So if you need
the length, try to get a hold on the underlying connection.

s/connection/collection/

Got confused on my new touchstream dvorak keyboard