gistfile1.txt

import os, sys, datetime

# Static variables
dateformat = {
	"eu": "%d.%m.%Y",
	"us": "%Y.%m.%d"
};


# Check that script is properly called
usageError = False
if(len(sys.argv) == 3):
	file, formatFrom, formatTo = sys.argv;
else:
	usageError = True

if(usageError or list(dateformat.keys()).index(formatFrom) < 0 or list(dateformat.keys()).index(formatTo) < 0):
	print('Usage: python ./rename.py [eu|us] [us|eu]');
	sys.exit();


# Define the rename function
def renameFiles(formatFrom, formatTo):
	for filename in os.listdir("."):
		filename = filename.strip()

		try:			
			if(os.path.isfile(filename)):
				filenameParts = os.path.splitext(filename);
			elif(os.path.isdir(filename)):
				filenameParts = (filename, '')
			else:
				continue;

			date = datetime.datetime.strptime(filenameParts[0],formatFrom)

			newFilename = date.strftime(formatTo) + filenameParts[1]

			os.rename(filename, newFilename)

			print("Renamed " + filename + " to " + newFilename);
		except ValueError as err:
			# Do nothing
			print(err)


# Execte function with given formatFrom and formatTo
renameFiles(dateformat[formatFrom], dateformat[formatTo])