update

Author: ausaki

ch07.md

@@ -145,6 +145,10 @@ w_object(PyObject *v, WFILE *p)
     ...
 ```
 
+## 解析 pyc 文件
+
+我自己写了一个 Python 脚本解析 pyc 文件，放在 [这里](codes/python_scripts/parse_pyc.py)
+
 ## dis
 
 Python 标准库中的 dis 模块可以用来获取代码对应的字节码。

ch09.md

@@ -0,0 +1,11 @@
+# Python虚拟机中的一般表达式
+
+这一章主要分析了 Python 虚拟机如何执行字节码表达式。想要了解具体信息可以阅读代码（src/Python/ceval.c 的PyEval_EvalFrameEx函数）。
+
+- LOAD_CONST
+- STORN_NAME
+- LOAD_NAME
+- BUILD_LIST
+- BUILD_NAME
+- 等等
+

ch10.md

@@ -0,0 +1,183 @@
+#  Python虚拟机中的控制流
+
+
+## if 控制流
+
+用到的代码：
+
+```python
+# if_control.py
+a = 1
+if a > 10:
+    prin "a > 10"
+elif a <= -2:
+    print "a <= -2"
+elif a != 1:
+    print "a != 1"
+elif a == 1:
+    print "a == 1"
+else:
+    print "Unknown a"
+
+```
+
+if_control.py 对应的字节码：
+
+```python
+  1           0 LOAD_CONST               0 (1)
+              3 STORE_NAME               0 (a)
+
+  2           6 LOAD_NAME                0 (a)
+              9 LOAD_CONST               1 (10)
+             12 COMPARE_OP               4 (>)
+             15 JUMP_IF_FALSE            9 (to 27)
+             18 POP_TOP
+
+  3          19 LOAD_CONST               2 ('a > 10')
+             22 PRINT_ITEM
+             23 PRINT_NEWLINE
+             24 JUMP_FORWARD            72 (to 99)
+        >>   27 POP_TOP
+
+  4          28 LOAD_NAME                0 (a)
+             31 LOAD_CONST               3 (-2)
+             34 COMPARE_OP               1 (<=)
+             37 JUMP_IF_FALSE            9 (to 49)
+             40 POP_TOP
+
+  5          41 LOAD_CONST               4 ('a <= -2')
+             44 PRINT_ITEM
+             45 PRINT_NEWLINE
+             46 JUMP_FORWARD            50 (to 99)
+        >>   49 POP_TOP
+
+  6          50 LOAD_NAME                0 (a)
+             53 LOAD_CONST               0 (1)
+             56 COMPARE_OP               3 (!=)
+             59 JUMP_IF_FALSE            9 (to 71)
+             62 POP_TOP
+
+  7          63 LOAD_CONST               5 ('a != 1')
+             66 PRINT_ITEM
+             67 PRINT_NEWLINE
+             68 JUMP_FORWARD            28 (to 99)
+        >>   71 POP_TOP
+
+  8          72 LOAD_NAME                0 (a)
+             75 LOAD_CONST               0 (1)
+             78 COMPARE_OP               2 (==)
+             81 JUMP_IF_FALSE            9 (to 93)
+             84 POP_TOP
+
+  9          85 LOAD_CONST               6 ('a == 1')
+             88 PRINT_ITEM
+             89 PRINT_NEWLINE
+             90 JUMP_FORWARD             6 (to 99)
+        >>   93 POP_TOP
+
+ 11          94 LOAD_CONST               7 ('Unknown a')
+             97 PRINT_ITEM
+             98 PRINT_NEWLINE
+        >>   99 LOAD_CONST               8 (None)
+            102 RETURN_VALUE
+None
+```
+
+## for 控制流
+
+用到的代码：
+
+```C
+// for_control.py
+lst = [1, 2]
+for i in lst:
+    print i
+```
+
+对应的字节码：
+
+```python
+  1           0 LOAD_CONST               0 (1)
+              3 LOAD_CONST               1 (2)
+              6 BUILD_LIST               2
+              9 STORE_NAME               0 (lst)
+
+  2          12 SETUP_LOOP              19 (to 34)
+             15 LOAD_NAME                0 (lst)
+             18 GET_ITER
+        >>   19 FOR_ITER                11 (to 33)
+             22 STORE_NAME               1 (i)
+
+  3          25 LOAD_NAME                1 (i)
+             28 PRINT_ITEM
+             29 PRINT_NEWLINE
+             30 JUMP_ABSOLUTE           19
+        >>   33 POP_BLOCK
+        >>   34 LOAD_CONST               2 (None)
+             37 RETURN_VALUE
+None
+```
+
+## while 控制流
+
+用到的代码：
+
+```C
+// while_control.py
+i = 0
+while i < 10:
+    i += 1
+    if i >= 5:
+        continue
+    if i == 20:
+        break
+    print i
+```
+
+对应的字节码：
+
+```python
+  1           0 LOAD_CONST               0 (0)
+              3 STORE_NAME               0 (i)
+
+  2           6 SETUP_LOOP              71 (to 80)
+        >>    9 LOAD_NAME                0 (i)
+             12 LOAD_CONST               1 (10)
+             15 COMPARE_OP               0 (<)
+             18 JUMP_IF_FALSE           57 (to 78)
+             21 POP_TOP
+
+  3          22 LOAD_NAME                0 (i)
+             25 LOAD_CONST               2 (1)
+             28 INPLACE_ADD
+             29 STORE_NAME               0 (i)
+
+  4          32 LOAD_NAME                0 (i)
+             35 LOAD_CONST               3 (5)
+             38 COMPARE_OP               5 (>=)
+             41 JUMP_IF_FALSE            7 (to 51)
+             44 POP_TOP
+
+  5          45 JUMP_ABSOLUTE            9
+             48 JUMP_FORWARD             1 (to 52)
+        >>   51 POP_TOP
+
+  6     >>   52 LOAD_NAME                0 (i)
+             55 LOAD_CONST               4 (20)
+             58 COMPARE_OP               2 (==)
+             61 JUMP_IF_FALSE            5 (to 69)
+             64 POP_TOP
+
+  7          65 BREAK_LOOP
+             66 JUMP_FORWARD             1 (to 70)
+        >>   69 POP_TOP
+
+  8     >>   70 LOAD_NAME                0 (i)
+             73 PRINT_ITEM
+             74 PRINT_NEWLINE
+             75 JUMP_ABSOLUTE            9
+        >>   78 POP_TOP
+             79 POP_BLOCK
+        >>   80 LOAD_CONST               5 (None)
+             83 RETURN_VALUE
+```             

codes/README.md

@@ -0,0 +1,9 @@
+# 书中涉及到的一些代码
+
+- small_python
+
+    非常简单的 python 解释器。
+
+- pytho_scripts
+
+    一些有用的 python 脚本，例如解析 pyc 文件的脚本。

codes/python_scripts/ch09/simple_obj.py

@@ -0,0 +1,4 @@
+i = 1
+s = "Python"
+d = {}
+l = []

codes/python_scripts/ch09/simple_obj.pyc

@@ -0,0 +1,3 @@
+lst = [1, 2]
+for i in lst:
+    print i

codes/python_scripts/ch10/for_control.py

@@ -0,0 +1,11 @@
+a = 1
+if a > 10:
+    print "a > 10"
+elif a <= -2:
+    print "a <= -2"
+elif a != 1:
+    print "a != 1"
+elif a == 1:
+    print "a == 1"
+else:
+    print "Unknown a"

codes/python_scripts/ch10/if_control.py

@@ -0,0 +1,8 @@
+i = 0
+while i < 10:
+    i += 1
+    if i >= 5:
+        continue
+    if i == 20:
+        break
+    print i

codes/python_scripts/ch10/while_control.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+import sys
+import os
+import dis
+
+pyfile = sys.argv[1]
+f_name = os.path.basename(pyfile)
+
+fp = open(pyfile)
+src = fp.read()
+fp.close()
+
+codeobj = compile(src, f_name, 'exec')
+
+print 'f_consts:', codeobj.co_consts
+print 'code:', codeobj.co_code.encode('hex')
+print 'lnotab:', codeobj.co_lnotab
+
+print dis.dis(codeobj)