How do we know if an item can be iterated

Question

I read some very old answers on this(10 years), and they say that in python 2.x this quality of iteration was just presumed.

But what about modern python like 3.9 ? Can I assume an item and object can be iterated ?

Abi

probably not the best way, but any object with an `__iter__` method is a good candidate for iteration — Paul H, Jun 10 '20 at 21:55
Asked and answered at https://stackoverflow.com/questions/1952464/in-python-how-do-i-determine-if-an-object-is-iterable — Amitai Irron, Jun 10 '20 at 22:04

score 2 · Accepted Answer · edited Jun 10 '20 at 23:03

2

Please refer below code and pass your object to find whether it is iterable or not.

def isiterable(obj):
  try:
     iter(obj)
     return True
  except TypeError:
     return False

Good Day!

edited Jun 10 '20 at 23:03

tmrlvi

answered Jun 10 '20 at 22:05

Earnest

score 0 · Answer 2 · answered Jun 10 '20 at 21:55

0

The shining new typing module is exactly for that. It contains all types.

from typing import Iterable
isinstance([], Iterable) # True
isinstance(None, Iterable) # False

answered Jun 10 '20 at 21:55

tmrlvi

``typing`` does not exist for runtime checking. The older ``collections.abc`` exists for this, e.g. ``collections.abc.Iterable``. – MisterMiyagi Jun 10 '20 at 22:06
Based on [collections.abs.Iterable](https://docs.python.org/3/library/collections.abc.html#collections.abc.Iterable) docs, we shouldn't use `isinstance` for iterables, as old style iterable are not identified by it. It seems that @Prince answer is the recommended way. – tmrlvi Jun 10 '20 at 22:31

2 Answers2