Get all object attributes in Python?

python

object-attributes

python-attributes

getattr

byAlex Kataev·Sep 14, 2024

Simple way to get an object's attributes in Python: use dir(). Exclude special methods by filtering out names starting with '__':

obj = MyClass()  # Assume MyClass is an intern at Hogwarts.
# I solemnly swear that I am up to no good (getting attributes)
print([attr for attr in dir(obj) if not attr.startswith('__')])

Key concept: Get a cleaner, refined attribute list by filtering out special methods from dir().

A deeper dive with `dict`

dir() gives a good picture, but complement it with __dict__ for an object's attribute dictionary:

attributes = dir(obj)
# Mischief managed (attributes detected)
details = {attr: getattr(obj, attr) for attr in attributes if not attr.startswith('__')}
print(details)

Using `getattr` for dynamic attributes

Dynamic objects have attributes resolved at runtime. Here's the gameplan: employ getattr(obj, attr):

# And let the games begin!
for attr in dir(obj):
    if not attr.startswith('__'):
        print(attr, getattr(obj, attr))  # GOAL! Attribute retrieved.

Beware the `dir` override

Just like a plot twist in a story, a __dir__ method can override what dir() returns. Keep that in mind!

The inheritance trail with `mro`

Uncover inherited attributes by traversing __mro__:

# Climbing the inheritance ladder
inherited_attrs = [attr for cls in obj.__class__.__mro__ for attr in dir(cls) if not attr.startswith('__')]

The whole picture: `dir()` + `dict`

Paint a complete picture by marrying dir() and __dict__:

class AdvancedToolbox:
    hammer = True
    screwdriver = False

    def __init__(self):
        self.wrench = True  # Aha! A wrench needed fixing.

# Tools meet obj: a perfect union
toolbox_attr = dir(AdvancedToolbox())
detailed_tools = {attr: getattr(AdvancedToolbox(), attr) for attr in toolbox_attr if not attr.startswith('__')}

This gives you every attribute, even those hidden in the deepest corners of the toolbox.

Navigate the minefield of dynamic attributes

When your object comes with dynamic attribute resolution via __getattr__, the path requires careful steps:

try:
    # Treading cautiously on the dynamic path...
    dynamic_value = getattr(obj, 'dynamic_attr')
except AttributeError:
    # Whoa! That was a close one.
    print('Attribute not found')