JupyterLab extension to inspect Python Bytecode.
Try the extension in your browser with Binder:
To install JupyterLab:
conda install -c conda-forge jupyterlab
jupyter labextension install jupyterlab-python-bytecode
Avanced Settings Editorto tweak some of the settings
See CONTRIBUTING.md to know how to contribute and setup a development environment.
Disassembling the Python code is done by connecting to a kernel, and sending the following code for evaluation from the lab extension:
import dis dis.dis(code_to_evaluate)
As mentioned in the documentation, there is not guarantee on the stability of the bytecode across Python versions:
Bytecode is an implementation detail of the CPython interpreter. No guarantees are made that bytecode will not be added, removed, or changed between versions of Python. Use of this module should not be considered to work across Python VMs or Python releases.
For example, if the Python file contains the following lines:
import math print(math.pi)
The following code will be sent to the kernel for evaluation:
import dis dis.dis(""" import math print(math.pi) """)
Which will return (example for CPython 3.6.6):
1 0 LOAD_CONST 0 (0) 2 LOAD_CONST 1 (None) 4 IMPORT_NAME 0 (math) 6 STORE_NAME 0 (math) 3 8 LOAD_NAME 1 (print) 10 LOAD_NAME 0 (math) 12 LOAD_ATTR 2 (pi) 14 CALL_FUNCTION 1 16 POP_TOP 18 LOAD_CONST 1 (None) 20 RETURN_VALUE
If you have several versions of Python installed on your machine (let's say in different conda environments), you can use the extension to check how the bytecode might differ.
The following example illustrates the introduction of the new
CALL_METHOD opcode introduced in CPython 3.7:
Original example from Disassembling Python Bytecode, by Peter Goldsborough