call_seq

call_seq is a tool that let you trace code easily. It record function call sequence. So you can learn how the process run.

How to install

pip install git+https://github.com/ya790206/call_seq

How to use

    from call_seq import CallSeq

    trail = CallSeq()
    trail.set_trace()
    # the code you want to trace.
    trail.unset_trace()
    trail.dump_to_file('output.json')

or

    $ python -m call_seq.core output.json demo1.py

Now you can read the output.json file.

The file output is maybe like

{
    "name": "<module>",
    "seq": [
        {
            "arguments": {},
            "code": "test()",
            "file_name": "demo.py",
            "lineno": 22,
            "name": "test",
            "return": "<NoneType>",
            "return_lineno": 16,
            "seq": [
                {
                    "arguments": {},
                    "code": "test1()",
                    "file_name": "demo.py",
                    "lineno": 14,
                    "name": "test1",
                    "return": "<int>: 2",
                    "return_lineno": 10,
                    "seq": [
                        {
                            "arguments": {},
                            "code": "test2()",
                            "file_name": "demo.py",
                            "lineno": 9,
                            "return": "<NoneType>",
                            "return_lineno": 5,
                            "seq": []
                        }
                    ]
                },
                {
                    "arguments": {},
                    "code": "test1()",
                    "file_name": "demo.py",
                    "lineno": 16,
                    "name": "test1",
                    "return": "<int>: 2",
                    "return_lineno": 10,
                    "seq": [
                        {
                            "arguments": {},
                            "code": "test2()",
                            "file_name": "demo.py",
                            "lineno": 9,
                            "return": "<NoneType>",
                            "return_lineno": 5,
                            "seq": []
                        }
                    ]
                }
            ]
        },
        {
            "arguments": {
                "self": "<CallSeq>"
            },
            "code": "map.unset_trace()",
            "file_name": "demo.py",
            "lineno": 23,
            "seq": [
                {
                    "arguments": {
                        "frame": "<NoneType>",
                        "trace_func": "<NoneType>"
                    },
                    "code": "set_trace(None)",
                    "file_name": "/home/ya790206/tmp_call_seq/call_seq/call_seq/core.py",
                    "lineno": 158,
                    "seq": []
                }
            ]
        }
    ]
}

You can open the file using browser.py

browser.py help you to trace code more easy.

    python -m call_seq.browser output.json

If you want to use browser.py, you need to install the below package.

    pyside
    pyqode.core
    pyqode.python

Known limit.

• You can't set_trace twice.
• It can't work with pdb or anything like pdb.
• set_trace and unset_trace need to be called in the same frame. So it doesn't work if you call set_trace in function A and call unset_trace in function B.