DateTime formatter den ich mir fuer mein REST backend schreiben musste

gistfile1.py

from django.http import HttpResponse
from django.http import Http404

from statistics.models import Sysinfo, CPUUsage
import json
from datetime import datetime
import re
import pdb

class DatetimeFormatter:		
    date_formats =                              \
    {			    	        	\
	'\d{4}-\d{2}-\d{2}$'	: '%Y-%m-%d',	\
	'\d{4}-\d{2}$'	    	: '%Y-%m',	\
	'\d{2}-\d{2}-\d{2}$'	: '%y-%m-%d',	\
	'\d{8}$'		: '%Y%m%d',	\
    }
	
    time_formats =  				\
    {	    					\
	'\d{2}:\d{2}:\d{2}$'	: '%H:%M:%S',	\
	'\d{2}:\d{2}$'	    	: '%H:%M',  	\
	'\d{2}$'    		: '%H',	    	\
	'\d{4}$'    		: '%H%M',   	\
	'\d{6}$'    		: '%H%M%S', 	\
    }
      
        
    @staticmethod
    def check_datetime_format(dt):
        dt = dt.rstrip().lstrip()
        # the splitter can be either a whitespace, a T or not there at all
	splitter = ''
	if ' ' in dt:
            splitter = ' '
	elif 'T' in dt:
	    splitter = 'T'

	# if time is given in UTC it ends with a Z
	ending = 'Z' if ('Z' in dt) else ''
		
	# format not supported
	if (splitter == '' or splitter == ' ') and ending == 'Z':
	    raise ValueError('datetime ' + dt + ' is of unsupported format')
			
	# if only one parameter is given it is either a date or a time	
	if splitter == '':	
	    try:
		f = DatetimeFormatter.check_date_format(dt)
	    except ValueError:
                try:
                    f = DatetimeFormatter.check_time_format(dt)
                except ValueError:
		    raise
	    return f
				
	# array contains date and time, if both are given
	date_time = dt.strip(ending).split(splitter)
		
	if len(date_time) == 2:
	    try:
		df = DatetimeFormatter.check_date_format(date_time[0])
		tf = DatetimeFormatter.check_time_format(date_time[1])
		return df + splitter + tf + ending
	    except ValueError:
		raise
	else:
             raise ValueError('Datetime "' + dt + '" is of unsupported format.')
			
			
    @staticmethod
    def check_date_format(d):
        # iterate supported formats
	for regex in DatetimeFormatter.date_formats:
	    if re.match(regex, d):
		return DatetimeFormatter.date_formats[regex]
	raise ValueError('Date "' + d + '" is of unsupported format.')
			
			
    @staticmethod
    def check_time_format(t):
	# iterate supported formats
	for regex in DatetimeFormatter.time_formats:
	    if re.match(regex, t):
		return DatetimeFormatter.time_formats[regex]
	raise ValueError('Time "' + t + '" is of unsupported format.')


    @staticmethod
    def get_datetime_from_format(dt, f):
        date_time = datetime.strptime(dt, f)
        if f in DatetimeFormatter.time_formats.values():
            date_time = datetime.combine(datetime.today().date(), date_time.time())
            
        return date_time