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/kjelly/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

from call_seq import trace

  @trace('output.json')
  def main():
      test()

  if __name__ == '__main__':
      with CallSeq(name='output.json'):
          test()

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": "inner",
  "seq": [
      {
          "arguments": {},
          "callee_file_name": "demo3.py",
          "callee_first_line": 19,
          "caller_code": "ret = func(*args, **kwargs)",
          "caller_file_name": "/home/ya790206/call_seq/call_seq/__init__.py",
          "lineno": 9,
          "name": "main",
          "return": "<NoneType>",
          "return_lineno": 21,
          "seq": [
              {
                  "arguments": {},
                  "callee_file_name": "demo3.py",
                  "callee_first_line": 13,
                  "caller_code": "test()",
                  "caller_file_name": "demo3.py",
                  "lineno": 21,
                  "name": "test",
                  "return": "<NoneType>",
                  "return_lineno": 16,
                  "seq": [
                      {
                          "arguments": {},
                          "callee_file_name": "demo3.py",
                          "callee_first_line": 8,
                          "caller_code": "test1()",
                          "caller_file_name": "demo3.py",
                          "lineno": 14,
                          "name": "test1",
                          "return": "<int>: 2",
                          "return_lineno": 10,
                          "seq": [
                              {
                                  "arguments": {},
                                  "callee_file_name": "demo3.py",
                                  "callee_first_line": 4,
                                  "caller_code": "test2()",
                                  "caller_file_name": "demo3.py",
                                  "lineno": 9,
                                  "return": "<NoneType>",
                                  "return_lineno": 5,
                                  "seq": []
                              }
                          ]
                      },
                      {
                          "arguments": {},
                          "callee_file_name": "demo3.py",
                          "callee_first_line": 8,
                          "caller_code": "test1()",
                          "caller_file_name": "demo3.py",
                          "lineno": 16,
                          "name": "test1",
                          "return": "<int>: 2",
                          "return_lineno": 10,
                          "seq": [
                              {
                                  "arguments": {},
                                  "callee_file_name": "demo3.py",
                                  "callee_first_line": 4,
                                  "caller_code": "test2()",
                                  "caller_file_name": "demo3.py",
                                  "lineno": 9,
                                  "return": "<NoneType>",
                                  "return_lineno": 5,
                                  "seq": []
                              }
                          ]
                      }
                  ]
              }
          ]
      },
      {
          "arguments": {
              "self": "<CallSeq>"
          },
          "callee_file_name": "/home/ya790206/call_seq/call_seq/core.py",
          "callee_first_line": 69,
          "caller_code": "trail.unset_trace()",
          "caller_file_name": "/home/ya790206/call_seq/call_seq/__init__.py",
          "lineno": 10,
          "seq": [
              {
                  "arguments": {
                      "frame": "<NoneType>",
                      "trace_func": "<NoneType>"
                  },
                  "callee_file_name": "/home/ya790206/call_seq/call_seq/utils.py",
                  "callee_first_line": 7,
                  "caller_code": "set_trace(None)",
                  "caller_file_name": "/home/ya790206/call_seq/call_seq/core.py",
                  "lineno": 70,
                  "seq": []
              }
          ]
      }
  ]
}

You can open the file using call_seq_browser

call_seq_browser help you to trace code more easy.

  python -m call_seq_browser output.json

See call_seq_browser for more.

Screen snapshot

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.

Special thanks

Thanks to JetBrains for providing pycharm open source license to the project.