// Include/cpython/frameobject.h
struct _frame {
PyObject_VAR_HEAD
struct _frame *f_back; /* previous frame, or NULL */
PyCodeObject *f_code; /* code segment */
PyObject *f_builtins; /* builtin symbol table (PyDictObject) */
PyObject *f_globals; /* global symbol table (PyDictObject) */
PyObject *f_locals; /* local symbol table (any mapping) */
PyObject **f_valuestack; /* points after the last local */
/* Next free slot in f_valuestack. Frame creation sets to f_valuestack.
Frame evaluation usually NULLs it, but a frame that yields sets it
to the current stack top. */
PyObject **f_stacktop;
PyObject *f_trace; /* Trace function */
char f_trace_lines; /* Emit per-line trace events? */
char f_trace_opcodes; /* Emit per-opcode trace events? */
/* Borrowed reference to a generator, or NULL */
PyObject *f_gen;
int f_lasti; /* Last instruction if called */
/* Call PyFrame_GetLineNumber() instead of reading this field
directly. As of 2.3 f_lineno is only valid when tracing is
active (i.e. when f_trace is set). At other times we use
PyCode_Addr2Line to calculate the line from the current
bytecode index. */
int f_lineno; /* Current line number */
int f_iblock; /* index in f_blockstack */
char f_executing; /* whether the frame is still executing */
PyTryBlock f_blockstack[CO_MAXBLOCKS]; /* for try and loop blocks */
PyObject *f_localsplus[1]; /* locals+stack, dynamically sized */
};
// Include/pyframe.h
typedef struct _frame PyFrameObject;
字节码
def sum(a, b):
return a + b
def test():
print('hello world')
print(sum(1, 2))
import dis
dis.dis(sum)
dis.dis(test)
2 0 LOAD_FAST 0 (a)
2 LOAD_FAST 1 (b)
4 BINARY_ADD
6 RETURN_VALUE
5 0 LOAD_GLOBAL 0 (print)
2 LOAD_CONST 1 ('hello world')
4 CALL_FUNCTION 1
6 POP_TOP
6 8 LOAD_GLOBAL 0 (print)
10 LOAD_GLOBAL 1 (sum)
12 LOAD_CONST 2 (1)
14 LOAD_CONST 3 (2)
16 CALL_FUNCTION 2
18 CALL_FUNCTION 1
20 POP_TOP
22 LOAD_CONST 0 (None)
24 RETURN_VALUE
行号，指令偏移，指令，参数，参数值（参考）
查看字节码：
sum.__code__.co_code
sum.__code__.co_varnames
sum.__code__.co_consts
sum.__code__.co_names
