Python字节码反汇编程序
Python标准库中的dis模块通过将其分解为易于理解的形式，提供了各种功能，可用于分析Python字节码。这有助于执行优化。字节码是解释器的特定于版本的实现细节。
dis()函数
该函数dis() 生成任何Python代码源的反汇编表示，即模块，类，方法，函数或代码对象。
>>> def hello():
print ("hello world")
>>> import dis
>>> dis.dis(hello)
2 0 LOAD_GLOBAL 0 (print)
3 LOAD_CONST 1 ('hello world')
6 CALL_FUNCTION 1 (1 positional, 0 keyword pair)
9 POP_TOP
10 LOAD_CONST 0 (None)
13 RETURN_VALUE字节码分析API在Bytecode类中定义。它的构造函数返回Bytecode对象，该对象具有以下方法来分析字节码
字节码()
这是构造函数。分析与函数，生成器，方法，源代码字符串或代码对象相对应的字节码。这是许多功能的便捷包装
>>> string=dis.Bytecode(hello)
>>> for x in string:
print (x)
Instruction(opname = 'LOAD_GLOBAL', opcode = 116, arg = 0, argval = 'print', argrepr = 'print', offset = 0, starts_line = 2, is_jump_target = False)
Instruction(opname = 'LOAD_CONST', opcode = 100, arg = 1, argval = 'hello world', argrepr = "'hello world'", offset = 3, starts_line = None, is_jump_target = False)
Instruction(opname = 'CALL_FUNCTION', opcode = 131, arg = 1, argval = 1, argrepr = '1 positional, 0 keyword pair', offset = 6, starts_line = None, is_jump_target = False)
Instruction(opname = 'POP_TOP', opcode = 1, arg = None, argval = None, argrepr = '', offset = 9, starts_line = None, is_jump_target = False)
Instruction(opname = 'LOAD_CONST', opcode = 100, arg = 0, argval = None, argrepr = 'None', offset = 10, starts_line = None, is_jump_target = False)
Instruction(opname = 'RETURN_VALUE', opcode = 83, arg = None, argval = None, argrepr = '', offset = 13, starts_line = None, is_jump_target = False)code_info()
此函数返回Python代码对象的信息。
>>> dis.code_info(hello) "Name: hello\nFilename: <pyshell#2>\nArgument count: 0\nKw-only arguments: 0\nNumber of locals: 0\nStack size: 2\nFlags: OPTIMIZED, NEWLOCALS, NOFREE\nConstants:\n 0: None\n 1: 'hello world'\nNames:\n 0: print"
show_code()
此函数打印Python模块，函数或类的详细代码信息。
>>> dis.show_code(hello) Name: hello Filename: <pyshell#2> Argument count: 0 Kw-only arguments: 0 Number of locals: 0 Stack size: 2 Flags: OPTIMIZED, NEWLOCALS, NOFREE Constants: 0: None 1: 'hello world' Names: 0: print
拆卸()
该函数反汇编一个代码对象，并提供划分为以下各列的输出-
行号，用于每行的第一条指令
当前指令，表示为->，
带标签的指令，用>>表示
指令的地址，
操作代码名称，
操作参数，以及
括号中参数的解释。
>>> codeInString = 'a = 5\nb = 6\nsum = a + b \ nprint("sum = ",sum)'
>>> codeObejct = compile(codeInString, 'sumstring', 'exec')
>>> dis.disassemble(codeObejct)输出结果
1 0 LOAD_CONST 0 (5)
3 STORE_NAME 0 (a)
2 6 LOAD_CONST 1 (6)
9 STORE_NAME 1 (b)
3 12 LOAD_NAME 0 (a)
15 LOAD_NAME 1 (b)
18 BINARY_ADD
19 STORE_NAME 2 (sum)
4 22 LOAD_NAME 3 (print)
25 LOAD_CONST 2 ('sum =')
28 LOAD_NAME 2 (sum)
31 CALL_FUNCTION 2 (2 positional, 0 keyword pair)
34 POP_TOP
35 LOAD_CONST 3 (None)
38 RETURN_VALUEget_instructions()
该函数在提供的函数，方法，源代码字符串或代码对象中的指令上返回迭代器。迭代器生成一系列名为元组的指令，在提供的代码中给出每个操作的详细信息。
>>> it=dis.get_instructions(code)
>>> for i in it:
print (i)
Instruction(opname = 'LOAD_CONST', opcode = 100, arg = 0, argval = <code object hello at 0x02A9BA70,
file "<disassembly>", line 2>, argrepr = '<code object hello at 0x02A9BA70, file "<disassembly>",
line 2>', offset = 0, starts_line = 2, is_jump_target = False)
Instruction(opname = 'LOAD_CONST', opcode = 100, arg = 1, argval = 'hello', argrepr = "'hello'", offset = 3, starts_line = None, is_jump_target = False)
Instruction(opname = 'MAKE_FUNCTION', opcode = 132, arg = 0, argval = 0, argrepr = '', offset = 6, starts_line = None, is_jump_target = False)
Instruction(opname = 'STORE_NAME', opcode = 90, arg = 0, argval = 'hello', argrepr = 'hello', offset = 9, starts_line = None, is_jump_target = False)
Instruction(opname = 'LOAD_CONST', opcode = 100, arg = 2, argval = None, argrepr = 'None', offset = 12, starts_line = None, is_jump_target = False)
Instruction(opname = 'RETURN_VALUE', opcode = 83, arg = None, argval = None, argrepr = '', offset = 15, starts_line = None, is_jump_target = False)函数信息是元组形式的对象，其参数如下所示-