new_contents: #
  # Copyright 2014 Quantopian, Inc.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  import os
  from unittest import TestCase
  from six import iteritems
  
  from zipline.utils import parse_args
  from zipline.utils import cli
  
  
  class TestParseArgs(TestCase):
      def test_defaults(self):
          args = parse_args([])
          for k, v in iteritems(cli.DEFAULTS):
              self.assertEqual(v, args[k])
  
      def write_conf_file(self):
          conf_str = """
  [Defaults]
  algofile=test.py
  symbols=test_symbols
  start=1990-1-1
          """
  
          with open('test.conf', 'w') as fd:
              fd.write(conf_str)
  
      def test_conf_file(self):
          self.write_conf_file()
          try:
              args = parse_args(['-c', 'test.conf'])
  
              self.assertEqual(args['algofile'], 'test.py')
              self.assertEqual(args['symbols'], 'test_symbols')
              self.assertEqual(args['start'], '1990-1-1')
              self.assertEqual(args['end'], cli.DEFAULTS['end'])
          finally:
              os.remove('test.conf')
  
      def test_overwrite(self):
          self.write_conf_file()
  
          try:
              args = parse_args(['-c', 'test.conf', '--start', '1992-1-1',
                                 '--algofile', 'test2.py'])
  
              # Overwritten values
              self.assertEqual(args['algofile'], 'test2.py')
              self.assertEqual(args['start'], '1992-1-1')
              # Non-overwritten values
              self.assertEqual(args['symbols'], 'test_symbols')
              # Default values
              self.assertEqual(args['end'], cli.DEFAULTS['end'])
          finally:
              os.remove('test.conf')
  
subject: Add tests for parse_args().