Automatic Key Finding

find_key.py

class MissingKeyException(Exception):
	"""
	If we can't figure out what the key is of an item being saved, we just say so.
 
	Should probably make a better error message that says what we can figure out and what they can do about it.
	"""
 
	def __init__(self, data_structure):
		self.ds = data_structure
 
	def __str__(self):
		return "Could not determine key for: %s" % self.ds.__repr__()
 
 def find_key(data_atom):
	"""
	Tries to find an appropriate S3 key from an arbitrary data structure
	"""
	if isinstance(data_atom, dict):
		if len(data_atom.keys()) == 1:
			current_key = data_atom.keys()[0]
		else:
			current_key = data_atom.get('key', False) or data_atom.get('title', False) or data_atom.get('name', False)
	elif isinstance(data_atom, list) or isinstance(data_atom, tuple):
		current_key = data_atom[0]
	else:
		raise MissingKeyException
	return current_key