Python Introspection: Difference between revisions
Line 17: | Line 17: | ||
<code>getmembers()</code> returns all members of an object as (name, value) pairs sorted by name. The object can be a module, class, etc. A predicate can be provided to the function, and the function returns only return members that satisfy a given predicate. | <code>getmembers()</code> returns all members of an object as (name, value) pairs sorted by name. The object can be a module, class, etc. A predicate can be provided to the function, and the function returns only return members that satisfy a given predicate. | ||
Example: | Example of how classes in a module can be identified: | ||
<syntaxhighlight lang='py'> | <syntaxhighlight lang='py'> | ||
import inspect | import inspect |
Revision as of 19:06, 8 July 2022
Internal
TODO
https://www.geeksforgeeks.org/code-introspection-in-python/
Overview
Introspection is Python's equivalent for Java reflection. It is the ability to determine the type of an object at runtime and to dynamically examine Python objects.
getattr()
getattr()
is a built-in function that returns the value of the specified attribute from the specified object.
The inspect Standard Library Module
inspect
is a Standard Library module.
getmembers()
getmembers()
returns all members of an object as (name, value) pairs sorted by name. The object can be a module, class, etc. A predicate can be provided to the function, and the function returns only return members that satisfy a given predicate.
Example of how classes in a module can be identified:
import inspect
modules = sys.modules.copy()
module = modules['some_package.some_subpackage.SomeClass']
class_tuples = inspect.getmembers(module, inspect.isclass)
for ct in class_tuples:
print('class name: ', ct[0])
print('class: ', ct[1])
Module Introspection
Also see:
Find classes in a module:
import inspect
module = sys.modules['some_package.some_subpackage.SomeClass']
class_tuples = inspect.getmembers(module, inspect.isclass)
for ct in class_tuples:
print('class name: ', ct[0])
print('class: ', ct[1])
Class Instance Introspection
Find Static Methods in a Class
A specific static method can be identified by querying the class attributes with inspect.getmembers()
and selecting the matching method, or by name with getattr()
builtin.
Find classes in a module:
import inspect
cls = ...qualification_method = getattr(ct[1], 'some_static_method')