def install_pip(self, package, save=True, save_dev=False):
        """Installs a pip package.

        :param save: if `True`, pins the package to the Hydrogen requirements
            YAML file.
        :param save_dev: if `True`, pins the package as a development
            dependency to the Hydrogen requirements YAML file.
        :param return: a **single** :class:`Requirement` object, representing
            the installed version of the given package.
        """
        requirement = Requirement.coerce(package)
        click.echo("pip install " + requirement.package)
        cmd = envoy.run("pip install {}".format(str(requirement)))
        if cmd.status_code == 0:
            installed_packages = get_installed_pypackages()
            package = installed_packages[requirement.package]
            requirement.version = "=={}".format(package.version)
            if save:
                self.requirements["all"].add(requirement)
            if save_dev:
                self.requirements["dev"].add(requirement)
            if save or save_dev:
                self.requirements.save()
            return requirement
        else:
            fatal(cmd.std_err)
def GetCompletions_NoSuggestions_Fallback_test( app ):
  # Python completer doesn't raise NO_COMPLETIONS_MESSAGE, so this is a
  # different code path to the Clang completer cases

  # TESTCASE2 (general_fallback/lang_python.py)
  RunTest( app, {
    'description': 'param jedi does not know about (id). query="a_p"',
    'request': {
      'filetype'  : 'python',
      'filepath'  : PathToTestFile( 'general_fallback',
                                    'lang_python.py' ),
      'line_num'  : 28,
      'column_num': 20,
      'force_semantic': False,
    },
    'expect': {
      'response': http.client.OK,
      'data': has_entries( {
        'completions': contains(
          CompletionEntryMatcher( 'a_parameter', '[ID]' ),
          CompletionEntryMatcher( 'another_parameter', '[ID]' ),
        ),
        'errors': empty(),
      } )
    },
  } )