First attempt at creating a script to migrate from parse (mongodb) to django

mongo_to_django.py

import json, datetime, math, os

model_names = ['Subscription']
for model_name in model_names:
  with open("%s.json"%model_name,'r') as f:
    subscriptions = json.loads(f.read())
  
  fields = {}
  max_lengths = {}
  nulls = {}

  assert(subscriptions.keys() == ['results'])

  for subscription in subscriptions['results']:
    for key,value in subscription.items():
      fields[key] = value
      max_lengths[key] = max(max_lengths.get(key,0),len(str(value)))
      if value == None:
        nulls[key] = value

  field_list = []

  class_names = {
    'int': 'IntegerField',
    'bool': 'BooleanField',
    'unicode': "CharField",
    'datetime': 'DateTime',
    'dict': "CharField",
  }

  print "class %s(models.Model):"%model_name

  for key,value in sorted(fields.items()):
    field_type = str(type(value)).split(u"'")[1]
    init_kwargs = ""
    try:
      datetime.datetime.strptime(value.split(".")[0],"%Y-%m-%dT%H:%M:%S")
      field_type = "datetime"
    except:
      pass
    python_class = class_names[field_type]

    max_length = 2**int(math.log(max_lengths[key],2)+1)
    if key in nulls:
      init_kwargs += "null=True,blank=True,"
    if python_class == "DateTime" and key == "updatedAt":
      init_kwargs += "auto_now=True,"
    if python_class == "CharField":
      init_kwargs += "max_length=%s,"%max_length

    print "\t%s = models.%s(%s)"%(key,python_class,init_kwargs)
    #print "{:>30}  {:10}  {}\t{}".format(key,field_type,max_lengths[key],max_length)