One-liner to check whether an iterator yields at least one element?

Question

Currently I\'m doing this:

try:
    something = iterator.next()
    # ...
except StopIteration:
    # ...

But I would like an expression th

Answer 1

This isn't really cleaner, but it shows a way to package it in a function losslessly:

def has_elements(iter):
  from itertools import tee
  iter, any_check = tee(iter)
  try:
    any_check.next()
    return True, iter
  except StopIteration:
    return False, iter

has_el, iter = has_elements(iter)
if has_el:
  # not empty

This isn't really pythonic, and for particular cases, there are probably better (but less general) solutions, like the next default.

first = next(iter, None)
if first:
  # Do something

This isn't general because None can be a valid element in many iterables.