List of classes in a directory (Python)

Question

I am developing a Python 2.6 package in which I would like to get a list of all classes in a specific directory (inside the package), then to introspect the class objects.

In particular, if the directory containing the current executable module has a sub-dir called foobar, and foobar contains .py files that define class Foo(MyBase), class Bar(MyBase)and class Bar2, I want to get a list of links to class objects that inherit from MyBase, i.e. Fooand Barbut not Bar2.

I am not sure if this task really requires any actions with the file system or if the modules in sub-dir are automatically loaded and simply need to be listed through introspection in some way. Any ideas here please? The sample code is very appreciated since I'm pretty new to Python, in particular introspection.

Answer 1

Modules are never loaded automatically, but they need to be easily sorted modulo in the directory and loaded using the built-in function __import__:

import os
import glob
for file in glob(os.path.join(os.path.dirname(os.path.abspath(__file__))), "*.py"):
    name = os.path.splitext(os.path.basename(file))[0]
    # add package prefix to name, if required
    module = __import__(name)
    for member in dir(module):
        # do something with the member named ``member``

Answer 2

Option 1: grep for "^ class (\ a \ w +) \ (Myclass" regexp with the -r option.

2: ( __init__.py), :

import mymodule
def itermodule(mod):
    for member in dir(mymod):
        ...

itermodule(mymodule)

Answer 3

, :

import glob
import importlib
import inspect
import os

current_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)))
current_module_name = os.path.splitext(os.path.basename(current_dir))[0]
for file in glob.glob(current_dir + "/*.py"):
     name = os.path.splitext(os.path.basename(file))[0]

     # Ignore __ files
     if name.startswith("__"):
         continue
     module = importlib.import_module("." + name,package=current_module_name)

     for member in dir(module):
         handler_class = getattr(module, member)

         if handler_class and inspect.isclass(handler_class):
             print member

, .

Answer 4

, ( @krakover):

• script,
  • ,
  • ( , )

---

import importlib
import inspect
import os
import glob


def import_plugins(plugins_package_directory_path, base_class=None, create_instance=True, filter_abstract=True):

    plugins_package_name = os.path.basename(plugins_package_directory_path)

    # -----------------------------
    # Iterate all python files within that directory
    plugin_file_paths = glob.glob(os.path.join(plugins_package_directory_path, "*.py"))
    for plugin_file_path in plugin_file_paths:
        plugin_file_name = os.path.basename(plugin_file_path)

        module_name = os.path.splitext(plugin_file_name)[0]

        if module_name.startswith("__"):
            continue

        # -----------------------------
        # Import python file

        module = importlib.import_module("." + module_name, package=plugins_package_name)

        # -----------------------------
        # Iterate items inside imported python file

        for item in dir(module):
            value = getattr(module, item)
            if not value:
                continue

            if not inspect.isclass(value):
                continue

            if filter_abstract and inspect.isabstract(value):
                continue

            if base_class is not None:
                if type(value) != type(base_class):
                    continue

            # -----------------------------
            # Instantiate / return type (depends on create_instance)

            yield value() if create_instance else value

:

SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
plugins_directory_path = os.path.join(SCRIPT_DIR, 'plugins')
plugins = import_plugins(plugins_directory_path, base_class=BasePlugin)

for plugin in plugins:
    plugin.foo()

• , plugins BasePlugin

Answer 5

egrep:

from subprocess import Popen, PIPE
from re import search

def get_classes(directory):
    job = Popen(['egrep', '-ir', '--include=*.py', 'class ', str(directory), ], stdout=PIPE)
    fileout, fileerr = job.communicate()
    if fileerr:
        raise Exception(fileerr)
    while directory[-1] == '/':
        directory = directory[:-1]
    found = []
    for line in fileout.split('\n'):
        match = search('^([^:]+).py:\s*class\s*(\S+)\s*\((\S+)\):', line)
        if match:
            pypath = match.group(1).replace(directory, '').replace('/', '.')[1:]
            cls = match.group(2)
            parents = filter(lambda x: x.strip, match.group(3).split())
            found.append((pypath, cls, parents, ))
    return found

get_classes('.'), egrep - :

./helpers/action.py:class Action(object):
./helpers/get_classes.py:    job = Popen(['egrep', '-ir', '--include=*.py', 'class ', str(directory), ], stdout=PIPE) # this is the get_classes script; not a valid result
./helpers/options.py:class Option(object):

, :

[('helpers.action', 'Action', ['object']), ('helpers.options', 'Option', ['object'])]

, < <24 > .