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_Basic_test( app ):
  filepath = PathToTestFile( 'basic.py' )
  completion_data = BuildRequest( filepath = filepath,
                                  filetype = 'python',
                                  contents = ReadFile( filepath ),
                                  line_num = 7,
                                  column_num = 3)

  results = app.post_json( '/completions',
                           completion_data ).json[ 'completions' ]

  assert_that( results,
               has_items(
                 CompletionEntryMatcher( 'a' ),
                 CompletionEntryMatcher( 'b' ),
                 CompletionLocationMatcher( 'line_num', 3 ),
                 CompletionLocationMatcher( 'line_num', 4 ),
                 CompletionLocationMatcher( 'column_num', 10 ),
                 CompletionLocationMatcher( 'filepath', filepath ) ) )