It has been a while since my last Python session but couple days ago I had a perfect opportunity for some Python scripting. The initial situation was that we had tons of files in a single directory. File names were UUIDs so the idea was to create subdirectories and move each file in right directory. We planned to have three levels of directories based on the first characters of the filename. So something starting with 4c14 would go under 4/c/1/.

I implemented this in two parts. The first part created the required directory structure:

import os

workPath = "/tmp/test/"
for a in range (0, 16):
   os.mkdir(workPath+hex(a)[2:])
   for b in range (0, 16):
      os.mkdir(workPath+"/"+hex(a)[2:]+"/"+hex(b)[2:])
      for c in range (0, 16):
         os.mkdir(workPath+"/"+hex(a)[2:]+"/"+hex(b)[2:]+"/"+hex(c)[2:])


The next part was to move files to the corresponding directories. This was also quite straightforward but I had problem with os.rename and I had to replace it with shutil.move. The original script worked fine on my home computer but the development server had the source and destination directories in different filesystems. Here is the final version:

import os
import shutil

sourceDir = "/tmp/files/"
destDir = "/tmp/test/"

filenames = os.listdir(sourceDir)
for filename in filenames:
   sourceFile = sourceDir+filename
   print(sourceFile)
   destFile = destDir+filename[0]+"/"+filename[1]+"/"+filename[2]+"/"+filename
   print(destFile)
   shutil.move(sourceFile, destFile)

These did not take too long to make and most likely someone who remembers Python libraries better would have done it in a fraction of time.