One of the counterarguments that you constantly hear about using python is that it is slow. This is somehow true for many cases, while most of the tools that scientist mainly use, like
pandas have big chunks written in
C, so they are very fast. For most of the geoscientific applications main advice would be to use vectorisation whenever possible, and avoid loops. However sometimes loops are unavoidable, and then python speed can get on to your nerves. Fortunately there are several easy ways to make your python loops faster.