Mathematical constants

[vanillajonathan]

There could be mathematical constants for pi, e and tau.

Example:

from numbers
filter number == math.pi

https://docs.python.org/3/library/math.html#constants

[PrettyWood]

@vanillajonathan pi and e (well math.exp(1)) should be available now (see #3909)
I reckon we can close this discussion