def raise_import_error_with_hint(dep):
    """Raises an import error and gives a helpful message for installing the
    missing dependency.

    :param dep: the missing dependency.

    """
    raise ImportError(
        '`{0}` is required. Install it with `pip install {0}` or `easy_install {0}` if you are not using pip. For more details, visit http://pip-installer.org.'
        .format(dep))
