import random
import string


def random_string_lower_numeric(size):
	"""
	Generate a random string of *size* length consisting of lowercase letters
	and numbers. This function is not meant for cryptographic purposes.

	:param int size: The length of the string to return.
	:return: A string consisting of random characters.
	:rtype: str
	"""
	# requirements = random, string
	return ''.join(random.choice(string.ascii_lowercase + string.digits) for x in range(size))