Refactoring
마틴파울러, 리팩터링 정리 1편 - http://asfirstalways.tistory.com/373
Python
Parallel Processing in Python: A Practical Guide with Examples - https://www.machinelearningplus.com/python/parallel-processing-python/
예외처리: try, except, else, finally - http://gomguard.tistory.com/122