AWS Credentials

credentials.py

import os

CREDENTIALS = ['AWSAccessKeyId', 'AWSSecretKey']


def credentials(filename=None):
	"""
	Generally made for standard AWS export format. Turns conf file into python dict
 
	If no filename is given, will attempt to read environment variables instead, then global variables
	"""
	if filename:
		var_list = filter(None, open(filename).read().split('\n'))
		credential_dict = dict([var.split('=') for var in var_list])
	elif set(CREDENTIALS).issubset(set(os.environ.keys())):  # Checking Environment Variables
		credential_dict = {var: os.environ.get[var] for var in CREDENTIALS}
	elif set(CREDENTIALS).issubset(set(globals().keys())):  # Checking Global Variables
		credential_dict = {var: globals()[var] for var in CREDENTIALS}
	else:
		raise MissingCredentialsException
	return credential_dict


class MissingCredentialsException(Exception):

	def __init__(self, credentials_dict):
		self.data = credentials_dict

	def value_check(self, test_key):
		"""
		Checks that the indicated key is present within the dict, the key has a non-false value, and is a string
		"""
		return (test_key in self.data and bool(self.data[test_key]) and isinstance(self.data[test_key], str))

	def __str__(self):
		validity_list = [self.value_check(credential) for credential in CREDENTIALS]
		missing_credential_list = filter(None, [a*b for a, b in zip(validity_list, CREDENTIALS)])
		return "Missing Expected Credentials: %s" % missing_credential_list.__repr__()