PyTracer

Prints function calls of the Python program.

$ cat example.py
def f(a):
    return g(a, "20")

def g(a, b):
    return b, a

f(10)
    
$ pytracer example.py
>example.<module>()
    >example.f(10)
        >example.g(10, '20') = ('20', 10)
    <example.f(10) = ('20', 10)
<example.<module>() = None

Installing

pip install pytracer

Usage

pytracer.py [-h] [-s S] [-i I] [-f F] filename ...

positional arguments:
  filename    a name of the Python program

optional arguments:
  -h, --help  show this help message and exit
  -s S        max argument length to print (the default is 32)
  -i I        modules to ignore (comma delimited, the default is
              re,glob,random,codecs,argparse)
  -f F        modules to focus at (comma delimited)

Advanced Usage

If you want to trace a single function just add the trace() decorator. Also it is possible to ignore not interesting subcalls:

import pytracer

@pytracer.no_trace()
def g():
    return 42

@pytracer.trace()
def f():
    return g()

f()

The module also can be used as a context manager:

import pytracer

def f():
    return 42

with pytracer.trace():
    f()