Ben Chuanlong Du's Blog

It is never too late to learn.

Numpy Arrays in Python

Tips and Traps

  1. The Pythonic way of checking whether a collection (string, list, set, dict, etc.) coll is non-empty is to use if coll. However, do NOT use if arr to check whether a numpy array is non-empty or not. Instead, you shoule use arr.size >0 to check whether a numpy array is non-empty or not.

ModuleNotFoundError: No Module Named _Ctypes in Python 3.7

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Issue

The error message "Modulenotfounderror: No Module Named _Ctypes" is thrown when intalling packages in Python 3.7.

Cause

libffi-dev is needed to cleanly build Python 3.7.

Solution

  1. Remove Python …