Recursively compare two directories to ensure they have the same files and subdirectories

Question

From what I observe filecmp.dircmp is recursive, but inadequate for my needs, at least in py2. I want to compare two directories and all their contained files. Do

Answer 1

filecmp.dircmp is the way to go. But it does not compare the content of files found with the same path in two compared directories. Instead filecmp.dircmp only looks at files attributes. Since dircmp is a class, you fix that with a dircmp subclass and override its phase3 function that compares files to ensure content is compared instead of only comparing os.stat attributes.

import filecmp

class dircmp(filecmp.dircmp):
    """
    Compare the content of dir1 and dir2. In contrast with filecmp.dircmp, this
    subclass compares the content of files with the same path.
    """
    def phase3(self):
        """
        Find out differences between common files.
        Ensure we are using content comparison with shallow=False.
        """
        fcomp = filecmp.cmpfiles(self.left, self.right, self.common_files,
                                 shallow=False)
        self.same_files, self.diff_files, self.funny_files = fcomp

Then you can use this to return a boolean:

import os.path

def is_same(dir1, dir2):
    """
    Compare two directory trees content.
    Return False if they differ, True is they are the same.
    """
    compared = dircmp(dir1, dir2)
    if (compared.left_only or compared.right_only or compared.diff_files 
        or compared.funny_files):
        return False
    for subdir in compared.common_dirs:
        if not is_same(os.path.join(dir1, subdir), os.path.join(dir2, subdir)):
            return False
    return True

In case you want to reuse this code snippet, it is hereby dedicated to the Public Domain or the Creative Commons CC0 at your choice (in addition to the default license CC-BY-SA provided by SO).