[Python-ideas] Exact decimal multiplication and division operations

I was making a "convert Fraction to Decimal, exactly if possible" function and ran into a wall: it's not possible to do some of the necessary operations with exact precision in decimal: - multiplication - division where the result can be represented exactly [the divisor is an integer whose prime factors are only two and five, or a rational number whose numerator qualifies] I assume there's some way around it that I haven't spent enough time to figure out [create a temporary context with sufficint digits for multiplication, and work out the reciprocal power of 10 by hand to use this multiplication to implement division], but I feel like these exact operations should be supported in the standard library.