Python程序的执行过程包括将源代码转换为字节码（即编译）以及执行字节码

$ python some-program.py

PI = 3.14def circle_area(r):    return PI * r ** 2class Person(object):    def __init__(self, name):        self.name = name    def say(self):        print('i am', self.name)

>>> text = open('D:myspacecodepythonCodemixdemo.py').read()>>> print(text)PI = 3.14def circle_area(r):    return PI * r ** 2class Person(object):    def __init__(self, name):        self.name = name    def say(self):        print('i am', self.name)

>>> result = compile(text,'D:myspacecodepythonCodemixdemo.py', 'exec')

>>> result<code object <module> at 0x000001DEC2FCF680, file "D:myspacecodepythonCodemixdemo.py", line 1>>>> result.__class__<class 'code'>

/* Bytecode object */struct PyCodeObject {    PyObject_HEAD    int co_argcount;            /* #arguments, except *args */    int co_posonlyargcount;     /* #positional only arguments */    int co_kwonlyargcount;      /* #keyword only arguments */    int co_nlocals;             /* #local variables */    int co_stacksize;           /* #entries needed for evaluation stack */    int co_flags;               /* CO_..., see below */    int co_firstlineno;         /* first source line number */    PyObject *co_code;          /* instruction opcodes */    PyObject *co_consts;        /* list (constants used) */    PyObject *co_names;         /* list of strings (names used) */    PyObject *co_varnames;      /* tuple of strings (local variable names) */    PyObject *co_freevars;      /* tuple of strings (free variable names) */    PyObject *co_cellvars;      /* tuple of strings (cell variable names) */    /* The rest aren't used in either hash or comparisons, except for co_name,       used in both. This is done to preserve the name and line number       for tracebacks and debuggers; otherwise, constant de-duplication       would collapse identical functions/lambdas defined on different lines.    */    Py_ssize_t *co_cell2arg;    /* Maps cell vars which are arguments. */    PyObject *co_filename;      /* unicode (where it was loaded from) */    PyObject *co_name;          /* unicode (name, for reference) */    PyObject *co_linetable;     /* string (encoding addr<->lineno mapping) See                                   Objects/lnotab_notes.txt for details. */    void *co_zombieframe;       /* for optimization only (see frameobject.c) */    PyObject *co_weakreflist;   /* to support weakrefs to code objects */    /* Scratch space for extra data relating to the code object.       Type is a void* to keep the format private in codeobject.c to force       people to go through the proper APIs. */    void *co_extra;    /* Per opcodes just-in-time cache     *     * To reduce cache size, we use indirect mapping from opcode index to     * cache object:     *   cache = co_opcache[co_opcache_map[next_instr - first_instr] - 1]     */    // co_opcache_map is indexed by (next_instr - first_instr).    //  * 0 means there is no cache for this opcode.    //  * n > 0 means there is cache in co_opcache[n-1].    unsigned char *co_opcache_map;    _PyOpcache *co_opcache;    int co_opcache_flag;  // used to determine when create a cache.    unsigned char co_opcache_size;  // length of co_opcache.};

>>> result.co_codeb'dx00Zx00dx01dx02x84x00Zx01Gx00dx03dx04x84x00dx04ex02x83x03Zx03dx05Sx00'

>>> result.co_names('PI', 'circle_area', 'object', 'Person')

>>> result.co_consts(3.14, <code object circle_area at 0x0000023D04D3F310, file "D:myspacecodepythonCodemixdemo.py", line 3>, 'circle_area', <code object Person at 0x0000023D04D3F5D0, file "D:myspacecodepythonCodemixdemo.py", line 6>, 'Person', None)

>>> person_code = result.co_consts[3]>>> person_code<code object Person at 0x0000023D04D3F5D0, file "D:myspacecodepythonCodemixdemo.py", line 6>>>> person_code.co_consts('Person', <code object __init__ at 0x0000023D04D3F470, file "D:myspacecodepythonCodemixdemo.py", line 7>, 'Person.__init__', <code object say at 0x0000023D04D3F520, file "D:myspacecodepythonCodemixdemo.py", line 10>, 'Person.say', None)

>>> import dis>>> dis.dis(result.co_code) 0 LOAD_CONST               0 (0) 2 STORE_NAME               0 (0) 4 LOAD_CONST               1 (1) 6 LOAD_CONST               2 (2) 8 MAKE_FUNCTION            010 STORE_NAME               1 (1)12 LOAD_BUILD_CLASS14 LOAD_CONST               3 (3)16 LOAD_CONST               4 (4)18 MAKE_FUNCTION            020 LOAD_CONST               4 (4)22 LOAD_NAME                2 (2)24 CALL_FUNCTION            326 STORE_NAME               3 (3)28 LOAD_CONST               5 (5)30 RETURN_VALUE

>>> result.co_consts[0]3.14

>>>dis.dis(result)  1           0 LOAD_CONST               0 (3.14)              2 STORE_NAME               0 (PI)  3           4 LOAD_CONST               1 (<code object circle_area at 0x0000023D04D3F310, file "D:myspacecodepythonCodemixdemo.py", line 3>)              6 LOAD_CONST               2 ('circle_area')              8 MAKE_FUNCTION            0             10 STORE_NAME               1 (circle_area)  6          12 LOAD_BUILD_CLASS             14 LOAD_CONST               3 (<code object Person at 0x0000023D04D3F5D0, file "D:myspacecodepythonCodemixdemo.py", line 6>)             16 LOAD_CONST               4 ('Person')             18 MAKE_FUNCTION            0             20 LOAD_CONST               4 ('Person')             22 LOAD_NAME                2 (object)             24 CALL_FUNCTION            3             26 STORE_NAME               3 (Person)             28 LOAD_CONST               5 (None)             30 RETURN_VALUEDisassembly of <code object circle_area at 0x0000023D04D3F310, file "D:myspacecodepythonCodemixdemo.py", line 3>:  4           0 LOAD_GLOBAL              0 (PI)              2 LOAD_FAST                0 (r)              4 LOAD_CONST               1 (2)              6 BINARY_POWER              8 BINARY_MULTIPLY             10 RETURN_VALUEDisassembly of <code object Person at 0x0000023D04D3F5D0, file "D:myspacecodepythonCodemixdemo.py", line 6>:  6           0 LOAD_NAME                0 (__name__)              2 STORE_NAME               1 (__module__)              4 LOAD_CONST               0 ('Person')              6 STORE_NAME               2 (__qualname__)  7           8 LOAD_CONST               1 (<code object __init__ at 0x0000023D04D3F470, file "D:myspacecodepythonCodemixdemo.py", line 7>)             10 LOAD_CONST               2 ('Person.__init__')             12 MAKE_FUNCTION            0             14 STORE_NAME               3 (__init__) 10          16 LOAD_CONST               3 (<code object say at 0x0000023D04D3F520, file "D:myspacecodepythonCodemixdemo.py", line 10>)             18 LOAD_CONST               4 ('Person.say')             20 MAKE_FUNCTION            0             22 STORE_NAME               4 (say)             24 LOAD_CONST               5 (None)             26 RETURN_VALUEDisassembly of <code object __init__ at 0x0000023D04D3F470, file "D:myspacecodepythonCodemixdemo.py", line 7>:  8           0 LOAD_FAST                1 (name)              2 LOAD_FAST                0 (self)              4 STORE_ATTR               0 (name)              6 LOAD_CONST               0 (None)              8 RETURN_VALUEDisassembly of <code object say at 0x0000023D04D3F520, file "D:myspacecodepythonCodemixdemo.py", line 10>: 11           0 LOAD_GLOBAL              0 (print)              2 LOAD_CONST               1 ('i am')              4 LOAD_FAST                0 (self)              6 LOAD_ATTR                1 (name)              8 CALL_FUNCTION            2             10 POP_TOP             12 LOAD_CONST               0 (None)             14 RETURN_VALUE

  1           0 LOAD_CONST               0 (3.14)              2 STORE_NAME               0 (PI)

>>> import demo