def get_change_log_for_app(app, from_version, to_version):
	change_log_folder = os.path.join(frappe.get_app_path(app), "change_log")
	if not os.path.exists(change_log_folder):
		return

	from_version = Version(from_version)
	to_version = Version(to_version)
	# remove pre-release part
	to_version.prerelease = None

	major_version_folders = ["v{0}".format(i) for i in xrange(from_version.major, to_version.major + 1)]
	app_change_log = []

	for folder in os.listdir(change_log_folder):
		if folder in major_version_folders:
			for file in os.listdir(os.path.join(change_log_folder, folder)):
				version = Version(os.path.splitext(file)[0][1:].replace("_", "."))

				if from_version < version <= to_version:
					file_path = os.path.join(change_log_folder, folder, file)
					content = frappe.read_file(file_path)
					app_change_log.append([version, content])

	app_change_log = sorted(app_change_log, key=lambda d: d[0], reverse=True)

	# convert version to string and send
	return [[cstr(d[0]), d[1]] for d in app_change_log]
dataset/ETHPy150Open frappe/frappe/frappe/utils/change_log.py/get_change_log_for_app/original