freeze.py 文件源码

def frozen(struct):
    """Return an immutable, hashable version of the given data structure.

    Iterators (including generators) are hashable but mutable, so they
    are evaluated and returned as tuples---if they are infinite, this
    function will not exit.
    """
    if isinstance(struct, Mapping):
        return frozenset((k, frozen(v)) for k, v in struct.items())
    if isinstance(struct, Set):
        return frozenset(frozen(item) for item in struct)
    if isinstance(struct, Iterable):  # Includes iterators and generators
        return tuple(frozen(item) for item in struct)
    hash(struct)  # Raise TypeError for unhashable objects
    return struct