bytecode 0.1

Python module to modify bytecode

bytecode is a Python module to modify bytecode.

• bytecode project homepage at GitHub (code, bugs)

• Download latest bytecode release at the Python Cheeseshop (PyPI)

Install bytecode: pip install bytecode.

bytecode only works on Python 3.

Hello World

Example running print('Hello World!'):

from bytecode import Instr, Bytecode

bytecode = Bytecode()
bytecode.extend([Instr("LOAD_NAME", 'print'),
                 Instr("LOAD_CONST", 'Hello World!'),
                 Instr("CALL_FUNCTION", 1),
                 Instr("POP_TOP"),
                 Instr("LOAD_CONST", None),
                 Instr("RETURN_VALUE")])
code = bytecode.to_code()
exec(code)

Output:

Hello World!

API

bytecode module version string: bytecode.__version__ (ex: '0.1').

Instruction

• Instr: abstract instruction, argument is not validated

• ConcreteInstr: concrete instruction, argument must be an integer

Create instructions

• Instr(name, arg=UNSET, *, lineno=None)

• ConcreteInstr(name, arg=UNSET, *, lineno=None)

• Instr.disassemble(code, offset)

• ConcreteInstr.disassemble(code, offset)

Pseudo instructions

• Label: target of jumps for Bytecode, must not be used in ConcreteBytecode

• SetLineno: set the line number of following instructions

Bytecode

• Bytecode: list of Instr

• BytecodeBlocks: list of blocks, a block is a list of Instr and has a label

• ConcreteBytecode: list of ConcreteInstr

Create bytecode

• Bytecode.from_code(*, extended_arg_op=False)

• BytecodeBlocks.from_code()

• ConcreteBytecode.from_code()

Conversions

• bytecode.to_bytecode() -> Bytecode

• bytecode.to_concrete_bytecode() -> ConcreteBytecode

• bytecode.to_bytecode_blocks() -> BytecodeBlocks

• bytecode.to_code() -> types.CodeType

ChangeLog

• 2016-02-26: Version 0.1

  • Rewrite completely the API!

• 2016-02-23: Release 0.0

  • First public release

See also

• codetransformer

• byteplay

• PEP 511 – API for code transformers