from typing import Mapping


def pretty(d, indent=0):
	""" Pretty printing of dictionary """
	ret_str = ''
	for key, value in d.items():

		if isinstance(value, Mapping):
			ret_str = ret_str + '\n' + '\t' * indent + str(key) + '\n'
			ret_str = ret_str + pretty(value, indent + 1)
		else:
			ret_str = ret_str + '\n' + '\t' * indent + str(key) + '\t' * (indent + 1) + ' => \n' + str(value) + '\n'

	return ret_str