Back in 2007, a user suggested a built-in prod() function with an API similar to the built-in sum() function.  The proposal was rejected because it wasn't needed often enough to justify a builtin function.  See https://bugs.python.org/issue1093

Though prod() doesn't meet the threshold for a builtin, it would be reasonable to add this to the math module (or an imath module).

Personally, I've wanted and written this function on several occasions (for applications such as multiplying probabilities).  On stack overflow, it has been a popular question with recurring interest.  See https://stackoverflow.com/questions/7948291/ and https://stackoverflow.com/questions/595374