Python port of the getContentHash() function from PHP's Composer. Useful when updating composer.lock from php when composer is available. Granted this "shouldn't be done" and is "doing it wrong", but sometimes running composer commands in your deployment chain is overkill and redundent.

getContentHash.py

import hashlib
from json import dumps
from collections import OrderedDict

# composerFileContents should be the dict version of the composer.json file
def getContentHash(composerFileContents):
	relevant = OrderedDict((key, composerFileContents[key]) for key in composerFileContents.keys() if key in ['name','version','require','require-dev','conflict','replace','provide','minimum-stability','prefer-stable','repositories','extra'])

	if 'config' in composerFileContents and 'platform' in composerFileContents['config']:
		relevant['config']['platform'] = composerFileContents['config']['platform']

	# hacky fix to cover the differences between JSON encoding in Python vs PHP
	encstr = dumps(OrderedDict((key, relevant[key]) for key in sorted(relevant.keys())),separators=(',', ':')).replace("/", "\\/").encode()

	return hashlib.md5(encstr).hexdigest()