Python/Codacy - Standard pseudo-random generators are not suitable for security/cryptographic purposes

Question

I have the following code

def get_random_date(year_start, year_end):
    return "%s-%s" % (random.randrange(year_start, year_end), random.randrange(1, 12))

and I'm getting the warning from Codacy: Standard pseudo-random generators are not suitable for security/cryptographic purposes.

What's should I rewrite this function to avoid such warning.