tracer python

tracer.py

import inspect

class TracerClass(object):

    def __init__(self):
        self.whitespace = '    '
        self.indent_lvl = 0
        self.watched_dir = T_CONTROLLERS_DIR

    def trace(self, frame, event, arg):

        co = frame.f_code
        fn_name = co.co_name
        ws = self.whitespace
        if fn_name == 'write':
            return
        line_no = frame.f_lineno
        filename_full = co.co_filename
        filename = path.basename(filename_full)
        if self.watched_dir in filename_full:

            if event == 'call':
                self.indent_lvl += 1
                arg_names = inspect.getargs(frame.f_code).args
                arg_dict = {name: frame.f_locals[name] for name in arg_names}
                text = ''
                for name, value in arg_dict.items():
                    if isinstance(value, (str, tuple, unicode, list, int, float)) or name == 'callback':
                        text += "%s=%s, " % (name, value)
                    else:
                        text += "%s=%s, " % (name, value.__class__.__name__)

                print('%s%s-call: ** %s ** (%s) in %s (%s)' % (
                    self.indent_lvl*ws, self.indent_lvl, fn_name, text, filename, line_no)
                )

                return self.trace

            elif event == 'return':
                if isinstance(arg, (str, tuple, unicode, list, int, float)):
                    print('%s%s-return: ** %s ** => %s' % (
                        self.indent_lvl*ws, self.indent_lvl, fn_name, arg)
                    )
                else:
                    print('%s%s-return: ** %s ** => %s' % (
                        self.indent_lvl*ws, self.indent_lvl, fn_name, arg.__class__.__name__)
                    )

                self.indent_lvl -= 1

TRACER = TracerClass()


def T(f):
    def decorated(*args, **kwargs):
        trace = sys.gettrace()
        sys.settrace(TRACER.trace)
        f(*args, **kwargs)
        sys.settrace(trace)
    return decorated