recursive os.makedirs 
recursive os.makedirs 

can't use exist_ok=T for py2 compatability
requires errno package which is part of python(?)
https://docs.python.org/2/library/errno.html
seems to be the best py2 solution: https://stackoverflow.com/questions/273192/how-can-i-safely-create-a-nested-directory/5032238#5032238
danforthcenter/plantcv,stiphyMT/plantcv,stiphyMT/plantcv,danforthcenter/plantcv,stiphyMT/plantcv,danforthcenter/plantcv