pyclbr – Python class browser support

Purpose:Implements an API suitable for use in a source code editor for making a class browser.
Available In:1.4 and later

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 below use this source file as input:

"""Example source for pyclbr.

class Base(object):
    """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. readmodule() takes the name of the module as argument returns a mapping of class names to Class objects containing the meta-data about the class source.

import pyclbr
import os
from operator import itemgetter

def show_class(name, class_data):
    print 'Class:', name
    print '\tFile: {0} [{1}]'.format(os.path.basename(class_data.file), 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(), key=itemgetter(1)):
        print '\tMethod: {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, basestring):
    if super_class_names:
        print '\tSuper 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 meta-data 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 below shows the classes and methods listed in order based on their line number in the source file.

$ python

Class: Base
        File: [10]
        Method: method1 [14]

Class: Sub1
        File: [17]
        Super classes: ['Base']

Class: Sub2
        File: [21]
        Super classes: ['Base']

Class: Mixin
        File: [25]
        Method: method2 [29]

Class: MixinUser
        File: [32]
        Super classes: ['Sub2', 'Mixin']
        Method: method1 [36]
        Method: method2 [39]
        Method: method3 [42]

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.

$ python

Function: my_function [45]

See also

The standard library documentation for this module.
The inspect module can discover more meta-data about classes and functions, but requires importing the code.
The tokenize module parses Python source code into tokens.