def parse_package(package:str):
    """
    Parse a package name

    if it is in the forme 'foo:bar' then 'foo' is the source, 
    and 'bar' is the (import) package name

    Returns the source name (for pip install) and the package name (for import)
    """
    l =  package.split(':')
    if len(l) == 1:
        source_name = package_name = l[0]
    else:
        source_name, package_name = l[:2]
    return source_name, package_name