Parsing class and function dependencies from a project

Question

I'm trying to run some analysis of class and function dependencies in a Python code base. My first step was to create a .csv file for import into Excel using Python's `csv` module and regular expressions. The current version of what I have looks like this: ``` import re import os import csv from os.path import join class ClassParser(object): class_expr = re.compile(r'class (.+?)(?:$(.+?)$)?:') python_file_expr = re.compile(r'^\w+[.]py$') def findAllClasses(self, python_file): """ Read in a python file and return all the class names """ with open(python_file) as infile: everything = infile.read() class_names = ClassParser.class_expr.findall(everything) return class_names def findAllPythonFiles(self, directory): """ Find all the python files starting from a top level directory """ python_files = [] for root, dirs, files in os.walk(directory): for file in files: if ClassParser.python_file_expr.match(file): python_files.append(join(root,file)) return python_files def parse(self, directo…

Accepted Answer

I've made a start on implementing this. Put the following code in a file, and run it, passing the name of a file or directory to analyse. It will print out all the classes it finds, the file it was found in, and the bases of the class. It is not intelligent, so if you have two `Foo` classes defined in your code base it will not tell you which one is being used, but it is a start.

This code uses the python `ast` module to examine `.py` files, and finds all the `ClassDef` nodes. It then uses this `meta` package to print bits of them out - you will need to install this package.

```
$ pip install -e git+https://github.com/srossross/Meta.git#egg=meta
```

Example output, run against django-featured-item:

```
$ python class-finder.py /path/to/django-featured-item/featureditem/
FeaturedField,../django-featured-item/featureditem/fields.py,models.BooleanField
SingleFeature,../django-featured-item/featureditem/tests.py,models.Model
MultipleFeature,../django-featured-item/featureditem/tests.py,models.Model
Author,../django-featured-item/featureditem/tests.py,models.Model
Book,../django-featured-item/featureditem/tests.py,models.Model
FeaturedField,../django-featured-item/featureditem/tests.py,TestCase
```

The code:

```
# class-finder.py
import ast
import csv
import meta
import os
import sys

def find_classes(node, in_file):
    if isinstance(node, ast.ClassDef):
        yield (node, in_file)

if hasattr(node, 'body'):
        for child in node.body:
            # `yield from find_classes(child)` in Python 3.x
            for x in find_classes(child, in_file): yield x

def print_classes(classes, out):
    writer = csv.writer(out)
    for cls, in_file in classes:
        writer.writerow([cls.name, in_file] +
            [meta.asttools.dump_python_source(base).strip()
                for base in cls.bases])

def process_file(file_path):
    root = ast.parse(open(file_path, 'r').read(), file_path)
    for cls in find_classes(root, file_path):
        yield cls

def process_directory(dir_path):
    for entry in os.listdir(dir_path):
        for cls in process_file_or_directory(os.path.join(dir_path, entry)):
            yield cls

def process_file_or_directory(file_or_directory):
    if os.path.isdir(file_or_directory):
        return process_directory(file_or_directory)
    elif file_or_directory.endswith('.py'):
        return process_file(file_or_directory)
    else:
        return []

if __name__ == '__main__':
    classes = process_file_or_directory(sys.argv[1])
    print_classes(classes, sys.stdout)
```

Parsing class and function dependencies from a project

Solution

Problem