Python/bltinmodule.c (part 2)

cpython 3.14 @ ab2d84fe1023/Python/bltinmodule.c ↗

This annotation covers the second half of Python/bltinmodule.c focusing on iteration and introspection built-ins. For print, len, type, isinstance, issubclass, range, repr, hash, and the numeric built-ins see the python_bltinmodule annotation.

Map

Lines	Symbol	Role
1-300	sorted, reversed	Sorting with Timsort; reversed sequence
301-600	zip, map, filter	Lazy iterator factories
601-800	any, all	Short-circuit Boolean iteration
801-1100	vars, dir, getattr, setattr, delattr	Object introspection and mutation
1101-1400	input, compile, exec, eval	Code execution
1401-3000	open, super, object, staticmethod, classmethod	Core class machinery

Reading

sorted

sorted(iterable, key=None, reverse=False) materialises the iterable into a list, then calls list.sort. The key function is applied once per element and the results are cached (decorate-sort-undecorate pattern internally managed by the sort comparator).

zip laziness

zip creates a zipobject that holds N iterators. Each __next__ call advances all N and returns a tuple. Exhaustion of any one iterator exhausts zip.

// CPython: Python/bltinmodule.c:430 zip_next
static PyObject *
zip_next(zipobject *lz)
{
    Py_ssize_t tuplesize = lz->tuplesize;
    PyObject *result = lz->result;
    ...
    for (Py_ssize_t i = 0; i < tuplesize; i++) {
        PyObject *it = PyTuple_GET_ITEM(lz->ittuple, i);
        PyObject *item = Py_TYPE(it)->tp_iternext(it);
        if (item == NULL) {
            ...
            return NULL;
        }
        ...
    }
    return result;
}

compile

compile(source, filename, mode) calls PyAST_obj2mod, PyAST_CompileObject, and returns a code object. The mode argument maps to the start token: 'exec' for statements, 'eval' for expressions, 'single' for the REPL.

super

super() with no arguments (zero-argument super) uses __class__ cell and the first argument of the enclosing function. The __class__ cell is implicitly created by the compiler when a method uses super().

gopy notes

vm/eval_simple.go handles GET_AWAITABLE, GET_YIELD_FROM_ITER, and many of the iteration opcodes. The super() zero-argument form requires the __class__ cell variable support in compile/codegen_expr_name.go. compile() maps to compile.Compile().