isiterable

isiterable is a Python module that provides the isiterable function, which acts as an object checker to know if it is iterable or not. It does not call the function and also has no undesirable performance numbers.

Features of isiterable

• Never call __iter__
• Functional for generators
• It's faster than tryiter or hasiter

Installation

pip install --upgrade isiterable

Usage

from isiterable import isiterable


print(isiterable(57890))  # False
print(isiterable([1, "Hello!"]))  # True

Using with classes

from isiterable import isiterable


class NoIters:
    def __init__(self, *args):
        self.args = args

    def __iter__(self):
        # isiterable will return False, Must be a generator :/
        return self.args


class YesIters:
    def __init__(self, *args):
        self.args = args

    def __iter__(self):
        # Works!
        for arg in args:
            yield arg


x = YesIters((1, 2))
res = isiterable(x)
print(res)  # True

x = NoIters("Hello!")
res = isiterable(x)
print(res)  # False

Other Examples

>>> from isiterable import isiterable
>>> isiterable(b"\x00\x01...")
True
>>> isiterable(callable)
False
>>> isiterable({"key1": True})
True
>>> isiterable([])
True

Alternatives to isiterable

If it doesn't match using isiterable, there are some solutions where you know which is better.

try-iter

This involves calling __iter__

try:
    iter(object)
except TypeError:
    pass

has-iter

this will check if the object has the attribute __iter__

if hasattr(object, "__iter__"):
    # ...

Benchmark

This small benchmark uses 3 code blocks:

• tryiter
• hasiter
• isiterable(object)

Where object is the argument to pass

Running benchmark.py will give results similar to this

Running 1,000,000 times each block of code...

Results of isiterable: 0.381
Results of hasiter   : 0.777
Results of tryiter   : 5.689

The best result is isiterable while tryiter having the worst result.