diff_settings.py

diff_settings.py

import os
import sys
import difflib
from pprint import pformat

settings1 = sys.argv[1]
settings2 = sys.argv[2]

 
def get_diff_msg(first, second, fromfile='First', tofile='Second'):
    """Return a unified diff between first and second."""
    # Force inputs to iterables for diffing.
    # use pformat instead of str or repr to output dicts and such
    # in a stable order for comparison.
    if isinstance(first, (tuple, list)):
        first = [pformat(d) for d in first]
    elif isinstance(first, dict):
        first = ["%s:%s" % (pformat(key), pformat(val)) for key,val in first.iteritems()]
    else:
        first = [pformat(first)]

    if isinstance(second, (tuple, list)):
        second = [pformat(d) for d in second]
    elif isinstance(second, dict):
        second = ["%s:%s" % (pformat(key), pformat(val)) for key,val in second.iteritems()]
    else:
        second = [pformat(second)]

    diff = difflib.ndiff(first, second)
    # Add line endings.
    return '\n' + ''.join([d + '\n' for d in diff])

KEYNOTFOUND = '<KEYNOTFOUND>'       # KeyNotFound for dictDiff

def dict_diff(first, second):
    """ Return a dict of keys that differ with another config object.  If a value is
        not found in one fo the configs, it will be represented by KEYNOTFOUND.
        @param first:   Fist dictionary to diff.
        @param second:  Second dicationary to diff.
        @return diff:   Dict of Key => (first.val, second.val)
    """
    diff = {}
    # Check all keys in first dict
    for key in first.keys():
        if (not second.has_key(key)):
            diff[key] = (first[key], KEYNOTFOUND)
        elif (first[key] != second[key]):
            diff[key] = (first[key], second[key])
    # Check all keys in second dict to find missing
    for key in second.keys():
        if (not first.has_key(key)):
            diff[key] = (KEYNOTFOUND, second[key])
    return diff


def get_settings(conf):
    settings_dict = {}
    for setting in conf.settings.get_all_members():
        if setting.upper() == setting and 'APPS' not in setting:
            settings_dict[setting] = getattr(conf.settings, setting)
    return settings_dict

os.environ['DJANGO_SETTINGS_MODULE'] = settings1
from django import conf
old_settings = get_settings(conf)
os.environ['DJANGO_SETTINGS_MODULE'] = settings2
reload(conf)
new_settings = get_settings(conf)

d = dict_diff(new_settings, old_settings)
for key, val in d.items():
    print key, get_diff_msg(val[0], val[1])