def create_set(package_list, delimiter):
    """
    Create a set of packages to be excluded.

    This function receives a list of strings, takes the packages' names
    and transforms them to a set.

    If the list contains packages with @ but the delimiter input is '==',
    then the package is ignored.

    Parameters
    ----------
    package_list : list
        List of strings with each element representing a package name
        and version.

    Returns
    -------
    set
        Set with the package names.
    """
    list_of_package_names = []
    for package in package_list:
        if delimiter in package:
            package_name = package.split(delimiter)
            list_of_package_names.append(package_name[0].strip())
    package_set = set(list_of_package_names)
    return package_set