Function getargs

IPython/core/ultratb.py:241–300

Get information about the arguments accepted by a code object. Three things are returned: (args, varargs, varkw), where 'args' is a list of argument names (possibly containing nested lists), and 'varargs' and 'varkw' are the names of the * and ** arguments or None.

(co)

# https://github.com/ipython/ipython/issues/8205 and
# https://github.com/ipython/ipython/issues/8293
def getargs(co):
    """Get information about the arguments accepted by a code object.

    Three things are returned: (args, varargs, varkw), where 'args' is
    a list of argument names (possibly containing nested lists), and
    'varargs' and 'varkw' are the names of the * and ** arguments or None."""
    if not iscode(co):
        raise TypeError('{!r} is not a code object'.format(co))

    nargs = co.co_argcount
    names = co.co_varnames
    args = list(names[:nargs])
    step = 0

    # The following acrobatics are for anonymous (tuple) arguments.
    for i in range(nargs):
        if args[i][:1] in ('', '.'):
            stack, remain, count = [], [], []
            while step < len(co.co_code):
                op = ord(co.co_code[step])
                step = step + 1
                if op >= dis.HAVE_ARGUMENT:
                    opname = dis.opname[op]
                    value = ord(co.co_code[step]) + ord(co.co_code[step+1])*256
                    step = step + 2
                    if opname in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'):
                        remain.append(value)
                        count.append(value)
                    elif opname in ('STORE_FAST', 'STORE_DEREF'):
                        if op in dis.haslocal:
                            stack.append(co.co_varnames[value])
                        elif op in dis.hasfree:
                            stack.append((co.co_cellvars + co.co_freevars)[value])
                        # Special case for sublists of length 1: def foo((bar))
                        # doesn't generate the UNPACK_TUPLE bytecode, so if
                        # `remain` is empty here, we have such a sublist.
                        if not remain:
                            stack[0] = [stack[0]]
                            break
                        else:
                            remain[-1] = remain[-1] - 1
                            while remain[-1] == 0:
                                remain.pop()
                                size = count.pop()
                                stack[-size:] = [stack[-size:]]
                                if not remain:
                                    break
                                remain[-1] = remain[-1] - 1
                            if not remain:
                                break
            args[i] = stack[0]

    varargs = None
    if co.co_flags & inspect.CO_VARARGS:
        varargs = co.co_varnames[nargs]
        nargs = nargs + 1
    varkw = None
    if co.co_flags & inspect.CO_VARKEYWORDS: