On Fri, May 22, 2020 at 10:23:06AM +0000, Rémi Lapeyre wrote:
> As you said the PEP would have to explain why not just use sympy and 
> honestly I don't have a very good argument there for now.

Because sympy is a beast. It's an excellent beast, but its an absolute 
monster. I stopped counting at 400 modules, not including tests. Having 
to install a mega-library like sympy to get two or three functions is 
overkill, like using a nuclear-powered bulldozer to crack a peanut.

The sympy docs say:

"SymPy does require mpmath Python library to be installed first. The 
recommended method of installation is through Anaconda, which includes 
mpmath, as well as several other useful libraries. Alternatively, some 
Linux distributions have SymPy packages available."

which is great if you are using Anaconda, a little less great if you're 
using Linux, and not very good if you're not using either.

And it's especially not very good if you are a student using a school 
laptop where Python is installed but you are not permitted to install 
other software. (Likewise for corporate users with locked down desktops, 
although they are less likely to care about prime numbers.)

sympy also comes with it's own odd ways of doing things, such as having 
to care about the difference between Python numbers and sympy numbers. 
(Not for prime testing, admittedly. I'm just making a general 
observation.)