A simple answer I have not seen yet is to just use the colour package.
Install via pip
pip install colour
Use as so:
from colour import Color
red = Color("red")
colors = list(red.range_to(Color("green"),10))
# colors is now a list of length 10
# Containing:
# [<Color red>, <Color #f13600>, <Color #e36500>, <Color #d58e00>, <Color #c7b000>, <Color #a4b800>, <Color #72aa00>, <Color #459c00>, <Color #208e00>, <Color green>]
Change the inputs to any colors you want. As noted by @zelusp, this will not restrict itself to a smooth combination of only two colors (e.g. red to blue will have yellow+green in the middle), but based on the upvotes it’s clear a number of folks find this to be a useful approximation