Is there a library or efficient way to perform multiplication in an arbitrary base in Python, without going through the conversion to base 10?

Example of the wanted function f in base 14:

base = 14
a = "b5"
b = "2a"
f(a,b,base) = "22b8"

For convenience, the above values converted in decimal:

int("b5", base) # 159
int("2a", base) # 38 
int("22b8", base) # 6042