hasNext in Python iterators? - Stack Overflow
stackoverflow.com › questions › 1966591Dec 27, 2009 · It is also possible to implement a helper generator that wraps any iterator and answers question if it has next value: Try it online! def has_next(it): first = True for e in it: if not first: yield True, prev else: first = False prev = e if not first: yield False, prev for has_next_, e in has_next(range(4)): print(has_next_, e)
Previous / current / next iterator in Python · GitHub
gist.github.com › mortenpi › 9604377AttributeError: 'list_iterator' object has no attribute 'next'. Instead you can use. def previous_current_next (iterable): """Make an iterator that yields an (previous, current, next) tuple per element. Returns None if the value does not make sense (i.e. previous before first and next after last). """ iterable = iter (iterable) prv = None cur = iterable.__next__ () try: while True: nxt = iterable.__next__ () yield (prv, cur, nxt) prv = cur cur = nxt except StopIteration: yield ...
Python Iterators and Generators
www.topcoder.com › python-iterators-and-generatorsOct 14, 2021 · Iterator protocol has iter and next methods. Both iterables and iterators have iter method that fetches an iterator. The thing that differentiates between iterators and iterables is the next method, that is part of just iterators. The next() method is used to fetch the next value of the iterable, whenever we use the print function with next.