pyclbr – Python class browser support
| Purpose: | Implements an API suitable for use in a source code editor for making a class browser. |
|---|---|
| Python Version: | 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):
return
class Sub1(Base):
"""This is the first subclass.
"""
class Sub2(Base):
"""This is the second subclass.
"""
class Mixin:
"""A mixin class.
"""
def method2(self):
return
class MixinUser(Sub2, Mixin):
"""Overrides method1 and method2
"""
def method1(self):
return
def method2(self):
return
def method3(self):
return
def my_function():
"""Stand-alone function.
"""
return
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)
print
return
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)
return
def show_super_classes(name, class_data):
super_class_names = []
for super_class in class_data.super:
if super_class == 'object':
continue
if isinstance(super_class, basestring):
super_class_names.append(super_class)
else:
super_class_names.append(super_class.name)
if super_class_names:
print '\tSuper classes:', super_class_names
return
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 pyclbr_readmodule.py
Class: Base
File: pyclbr_example.py [10]
Method: method1 [14]
Class: Sub1
File: pyclbr_example.py [17]
Super classes: ['Base']
Class: Sub2
File: pyclbr_example.py [21]
Super classes: ['Base']
Class: Mixin
File: pyclbr_example.py [25]
Method: method2 [29]
Class: MixinUser
File: pyclbr_example.py [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 pyclbr_readmodule_ex.py
Function: my_function [45]See also
- pyclbr
- The standard library documentation for this module.
- inspect
- The inspect module can discover more meta-data about classes and functions, but requires importing the code.
- tokenize
- The tokenize module parses Python source code into tokens.
The canonical version of this article
