python 源码解读2
http://www.jianshu.com/users/4d4a2f26740b/latest_articles
http://blog.csdn.net/ssjhust123/article/category/3202957
http://tech.uc.cn/?p=1932
>>>src=open("./test.py").read()>>>co=compile(src,"test.py","exec")
>>>dir(co)
>>> dir(co)
[\'__class__\', \'__cmp__\', \'__delattr__\', \'__doc__\', \'__eq__\', \'__format__\',
\'__ge__\', \'__getattribute__\', \'__gt__\', \'__hash__\', \'__init__\', \'__le__\',
\'__lt__\', \'__ne__\', \'__new__\', \'__reduce__\', \'__reduce_ex__\', \'__repr__\',
\'__setattr__\', \'__sizeof__\', \'__str__\', \'__subclasshook__\', \'co_argcount\',
\'co_cellvars\', \'co_code\', \'co_consts\', \'co_filename\', \'co_firstlineno\',
\'co_flags\', \'co_freevars\', \'co_lnotab\', \'co_name\', \'co_names\', \'co_nlocals\',
\'co_stacksize\', \'co_varnames\']
>>> print co.co_names
(\'a\', \'b\', \'c\', \'d\', \'object\', \'Student\', \'func\', \'bart\', \'name\', \'score\')
>>> print co.co_consts
(\'hello\', 1, 1.0, \'100\', \'Student\', <code object Student at 0x7f1d2b7a2918, file "test.py", line 5>,
<code object func at 0x7f1d2b7a25d0, file "test.py", line 9>, \'this is name\', \'this is score\', None)
>>> co.co_code
\'d\x00\x00Z\x00\x00d\x01\x00Z\x01\x00d\x02\x00Z\x02\x00d\x03\x00Z\x03\x00d\
x04\x00e\x04\x00f\x01\x00d\x05\x00\x84\x00\x00\x83\x00\x00YZ\x05\x00d\x06\x00\
x84\x00\x00Z\x06\x00e\x06\x00\x83\x00\x00\x01e\x05\x00d\x07\x00d\x08\x00\x83\
x02\x00Z\x07\x00e\x07\x00i\x08\x00GHe\x07\x00i\t\x00GHd\t\x00S\'
>>> import dis
>>> print dis.dis(co)
1 0 LOAD_CONST 0 (\'hello\')
3 STORE_NAME 0 (a)
2 6 LOAD_CONST 1 (1)
9 STORE_NAME 1 (b)
3 12 LOAD_CONST 2 (1.0)
15 STORE_NAME 2 (c)
4 18 LOAD_CONST 3 (\'100\')
21 STORE_NAME 3 (d)
5 24 LOAD_CONST 4 (\'Student\')
27 LOAD_NAME 4 (object)
30 BUILD_TUPLE 1
33 LOAD_CONST 5 (<code object Student at 0x7f1d2b7a2918, file "test.py", line 5>)
36 MAKE_FUNCTION 0
39 CALL_FUNCTION 0
42 BUILD_CLASS
43 STORE_NAME 5 (Student)
9 46 LOAD_CONST 6 (<code object func at 0x7f1d2b7a25d0, file "test.py", line 9>)
49 MAKE_FUNCTION 0
52 STORE_NAME 6 (func)
11 55 LOAD_NAME 6 (func)
58 CALL_FUNCTION 0
61 POP_TOP
12 62 LOAD_NAME 5 (Student)
65 LOAD_CONST 7 (\'this is name\')
68 LOAD_CONST 8 (\'this is score\')
71 CALL_FUNCTION 2
74 STORE_NAME 7 (bart)
13 77 LOAD_NAME 7 (bart)
80 LOAD_ATTR 8 (name)
83 PRINT_ITEM
84 PRINT_NEWLINE
14 85 LOAD_NAME 7 (bart)
88 LOAD_ATTR 9 (score)
91 PRINT_ITEM
92 PRINT_NEWLINE
93 LOAD_CONST 9 (None)
96 RETURN_VALUE
None
-----------------------------------------------------------
typedef struct _frame {
PyObject_VAR_HEAD
struct _frame *f_back; /* 调用者的帧 */
PyCodeObject *f_code; /* 帧对应的字节码对象 */
PyObject *f_builtins; /* 内置名字空间 */
PyObject *f_globals; /* 全局名字空间 */
PyObject *f_locals; /* 本地名字空间 */
PyObject **f_valuestack; /* 运行时栈底 */
PyObject **f_stacktop; /* 运行时栈顶 */
…….
}
typedef struct {
PyObject_HEAD
int co_argcount; /* 位置参数个数 */
int co_nlocals; /* 局部变量个数 */
int co_stacksize; /* 栈大小 */
int co_flags;
PyObject *co_code; /* 字节码指令序列 */
PyObject *co_consts; /* 所有常量集合 */
PyObject *co_names; /* 所有符号名称集合 */
PyObject *co_varnames; /* 局部变量名称集合 */
PyObject *co_freevars; /* 闭包用的的变量名集合 */
PyObject *co_cellvars; /* 内部嵌套函数引用的变量名集合 */
/* The rest doesn’t count for hash/cmp */
PyObject *co_filename; /* 代码所在文件名 */
PyObject *co_name; /* 模块名|函数名|类名 */
int co_firstlineno; /* 代码块在文件中的起始行号 */
PyObject *co_lnotab; /* 字节码指令和行号的对应关系 */
void *co_zombieframe; /* for optimization only (see frameobject.c) */
} PyCodeObject;
-----------------------------------------------------------------------
[root@monitor ~]# vi test.py
a="hello"
b=1
c=1.0
d=\'100\'
class Student(object):
def __init__(self, name, score):
self.name = name
self.score = score
def func():
a="hello"
b=1
c=1.0
d=\'100\'
class Student(object):
def __init__(self, name, score):
self.name = name
self.score = score
def func():
import sys
frame = sys._getframe()
print frame.f_locals
print frame.f_globals
print frame.f_back.f_locals
print a
func()
[root@monitor ~]# python test.py
{ \'sys\': <module \'sys\' (built-in)>,
\'frame\': <frame object at 0x1569750>
}
{\'a\': \'hello\',
\'c\': 1.0,
\'b\': 1,
\'func\': <function func at 0x7facf5cbbc08>,
\'d\': \'100\',
\'__builtins__\': <module \'__builtin__\' (built-in)>,
\'__file__\': \'test.py\',
\'__package__\': None,
\'Student\': <class \'__main__.Student\'>,
\'__name__\': \'__main__\',
\'__doc__\': None
}
{\'a\': \'hello\',
\'c\': 1.0,
\'b\': 1,
\'func\': <function func at 0x7facf5cbbc08>,
\'d\': \'100\',
\'__builtins__\': <module \'__builtin__\' (built-in)>,
\'__file__\': \'test.py\',
\'__package__\': None,
\'Student\': <class \'__main__.Student\'>,
\'__name__\': \'__main__\', \'__doc__\': None
}
hello
this is name
this is score
------------------------------------------------------------------------
a="hello"
def func():
import sys
frame = sys._getframe()
print frame.f_locals
print frame.f_globals
print frame.f_back.f_locals
print a
"test.py" 12L, 165C written
[root@monitor ~]# python test.py
{ \'sys\': <module \'sys\' (built-in)>,
\'frame\': <frame object at 0xb67d30>}
{ \'a\': \'hello\',
\'__builtins__\': <module \'__builtin__\' (built-in)>,
\'__file__\': \'test.py\',
\'__package__\': None,
\'func\': <function func at 0x7fc658a87938>,
\'__name__\': \'__main__\',
\'__doc__\': None}
{ \'a\': \'hello\',
\'__builtins__\': <module \'__builtin__\' (built-in)>,
\'__file__\': \'test.py\',
\'__package__\': None,
\'func\': <function func at 0x7fc658a87938>,
\'__name__\': \'__main__\',
\'__doc__\': None}
hello
-----------------------------------------------------------
>>> src=open("./test.py").read()
>>> co=compile(src,"test.py","exec")
>>> co.co_consts
(\'hello\', <code object func at 0x7f1f75deb558, file "test.py", line 4>, None)
>>> import dis
>>> dis.dis(co.co_consts[1])
5 0 LOAD_CONST 1 (-1)
3 LOAD_CONST 0 (None)
6 IMPORT_NAME 0 (sys)
9 STORE_FAST 0 (sys)
6 12 LOAD_FAST 0 (sys)
15 LOAD_ATTR 1 (_getframe)
18 CALL_FUNCTION 0
21 STORE_FAST 1 (frame)
7 24 LOAD_FAST 1 (frame)
27 LOAD_ATTR 2 (f_locals)
30 PRINT_ITEM
31 PRINT_NEWLINE
8 32 LOAD_FAST 1 (frame)
35 LOAD_ATTR 3 (f_globals)
38 PRINT_ITEM
39 PRINT_NEWLINE
9 40 LOAD_FAST 1 (frame)
43 LOAD_ATTR 4 (f_back)
46 LOAD_ATTR 2 (f_locals)
49 PRINT_ITEM
50 PRINT_NEWLINE
10 51 LOAD_GLOBAL 5 (a)
54 PRINT_ITEM
55 PRINT_NEWLINE
56 LOAD_CONST 0 (None)
>>> print co.co_names
(\'a\', \'func\')
>>> print co.co_consts
(\'hello\', <code object func at 0x7f1f75deb558, file "test.py", line 4>, None)
第一列表示以下几个指令在py文件中的行号;
第二列是该指令在指令序列co_code里的偏移量;
第三列是指令opcode的名称，分为有操作数和无操作数两种，opcode在指令序列中是一个字节的整数;
第四列是操作数oparg，在指令序列中占两个字节，基本都是co_consts或者co_names的下标;
第五列带括号的是操作数说明。
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