Function getclosurevars

Lib/inspect.py:1510–1563

Get the mapping of free variables to their current values. Returns a named tuple of dicts mapping the current nonlocal, global and builtin references as seen by the body of the function. A final set of unbound names that could not be resolved is also provided.

(func)

ClosureVars = namedtuple('ClosureVars', 'nonlocals globals builtins unbound')

def getclosurevars(func):
    """
    Get the mapping of free variables to their current values.

    Returns a named tuple of dicts mapping the current nonlocal, global
    and builtin references as seen by the body of the function. A final
    set of unbound names that could not be resolved is also provided.
    """

    if ismethod(func):
        func = func.__func__

    if not isfunction(func):
        raise TypeError("{!r} is not a Python function".format(func))

    code = func.__code__
    # Nonlocal references are named in co_freevars and resolved
    # by looking them up in __closure__ by positional index
    if func.__closure__ is None:
        nonlocal_vars = {}
    else:
        nonlocal_vars = {
            var : cell.cell_contents
            for var, cell in zip(code.co_freevars, func.__closure__)
       }

    # Global and builtin references are named in co_names and resolved
    # by looking them up in __globals__ or __builtins__
    global_ns = func.__globals__
    builtin_ns = global_ns.get("__builtins__", builtins.__dict__)
    if ismodule(builtin_ns):
        builtin_ns = builtin_ns.__dict__
    global_vars = {}
    builtin_vars = {}
    unbound_names = set()
    global_names = set()
    for instruction in dis.get_instructions(code):
        opname = instruction.opname
        name = instruction.argval
        if opname == "LOAD_ATTR":
            unbound_names.add(name)
        elif opname == "LOAD_GLOBAL":
            global_names.add(name)
    for name in global_names:
        try:
            global_vars[name] = global_ns[name]
        except KeyError:
            try:
                builtin_vars[name] = builtin_ns[name]
            except KeyError:
                unbound_names.add(name)

    return ClosureVars(nonlocal_vars, global_vars,
                       builtin_vars, unbound_names)

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