How do I enumerate functions of a Python class?

Python provides several ways to enumerate (list) the functions and methods of a class. The most common approach uses the inspect module to examine class members and filter for callable methods.

Using inspect.getmembers()

The inspect.getmembers() function returns all members of a class. Use inspect.isfunction or inspect.ismethod as a predicate to filter only functions ?

import inspect

class SampleClass:
    def __init__(self):
        self.x = 10
    
    def method_one(self):
        return "First method"
    
    def method_two(self):
        return "Second method"

# Get all methods using inspect
methods = inspect.getmembers(SampleClass, predicate=inspect.isfunction)
print("Class methods:")
for name, method in methods:
    print(f"  {name}: {method}")

Class methods:
  __init__: <function SampleClass.__init__ at 0x...>
  method_one: <function SampleClass.method_one at 0x...>
  method_two: <function SampleClass.method_two at 0x...>

Using dir() Function

The dir() function lists all attributes of a class. Filter callable attributes using callable() ?

class SampleClass:
    def __init__(self):
        self.x = 10
    
    def method_one(self):
        return "First method"
    
    def method_two(self):
        return "Second method"

# Get callable attributes using dir()
all_attributes = dir(SampleClass)
methods = [attr for attr in all_attributes if callable(getattr(SampleClass, attr))]

print("Callable methods:")
for method in methods:
    if not method.startswith('_'):  # Exclude private methods
        print(f"  {method}")

Callable methods:
  method_one
  method_two

Getting Only User-Defined Methods

To exclude built-in methods like __init__, filter out methods starting with underscores ?

import inspect

class SampleClass:
    def __init__(self):
        self.x = 10
    
    def method_one(self):
        return "First method"
    
    def method_two(self):
        return "Second method"

# Get only user-defined methods
methods = inspect.getmembers(SampleClass, predicate=inspect.isfunction)
user_methods = [(name, method) for name, method in methods if not name.startswith('_')]

print("User-defined methods:")
for name, method in user_methods:
    print(f"  {name}")

User-defined methods:
  method_one
  method_two

Comparison

Conclusion

Use inspect.getmembers() with inspect.isfunction for comprehensive method enumeration. Use dir() for simple attribute listing. Filter with underscore checks to exclude built-in methods.