pyclbr — Class Browser

Purpose:Implements an API suitable for use in a source code editor for making a class browser.

pyclbr can scan Python source to find classes and stand-alone functions. The information about class, method, and function names and line numbers is gathered using tokenize without importing the code.

The examples in this section use the following source file as input.
"""Example source for pyclbr.

class Base:
    """This is the base class.

    def method1(self):

class Sub1(Base):
    """This is the first subclass.

class Sub2(Base):
    """This is the second subclass.

class Mixin:
    """A mixin class.

    def method2(self):

class MixinUser(Sub2, Mixin):
    """Overrides method1 and method2

    def method1(self):

    def method2(self):

    def method3(self):

def my_function():
    """Stand-alone function.

Scanning for Classes

There are two public functions exposed by pyclbr. The first, readmodule(), takes the name of the module as argument returns a mapping of class names to Class objects containing the metadata about the class source.
import pyclbr
import os
from operator import itemgetter

def show_class(name, class_data):
    print('Class:', name)
    filename = os.path.basename(class_data.file)
    print('  File: {0} [{1}]'.format(
        filename, class_data.lineno))
    show_super_classes(name, class_data)
    show_methods(name, class_data)

def show_methods(class_name, class_data):
    for name, lineno in sorted(class_data.methods.items(),
        print('  Method: {0} [{1}]'.format(name, lineno))

def show_super_classes(name, class_data):
    super_class_names = []
    for super_class in class_data.super:
        if super_class == 'object':
        if isinstance(super_class, str):
    if super_class_names:
        print('  Super classes:', super_class_names)

example_data = pyclbr.readmodule('pyclbr_example')

for name, class_data in sorted(example_data.items(),
                               key=lambda x: x[1].lineno):
    show_class(name, class_data)

The metadata for the class includes the file and line number where it is defined, as well as the names of super classes. The methods of the class are saved as a mapping between method name and line number. The output shows the classes and methods listed in order based on their line number in the source file.

$ python3

Class: Base
  File: [11]
  Method: method1 [15]

Class: Sub1
  File: [19]
  Super classes: ['Base']

Class: Sub2
  File: [24]
  Super classes: ['Base']

Class: Mixin
  File: [29]
  Method: method2 [33]

Class: MixinUser
  File: [37]
  Super classes: ['Sub2', 'Mixin']
  Method: method1 [41]
  Method: method2 [44]
  Method: method3 [47]

Scanning for Functions

The other public function in pyclbr is readmodule_ex(). It does everything that readmodule() does, and adds functions to the result set.
import pyclbr
import os
from operator import itemgetter

example_data = pyclbr.readmodule_ex('pyclbr_example')

for name, data in sorted(example_data.items(),
                         key=lambda x: x[1].lineno):
    if isinstance(data, pyclbr.Function):
        print('Function: {0} [{1}]'.format(name, data.lineno))

Each Function object has properties much like the Class object.

$ python3

Function: my_function [51]

See also