Python Playground - Event tracing : call(), return, line, etc.: Online Interpreter, Compiler & Editor

import sys
def tracer(frame, event, arg):
  print("> Event: ", event, 
    " @", frame.f_lineno, 
    " Cmd: ", frame.f_locals.get('cmd'), 
    " Arg: ", arg, 
    # frame.f_locals, # show messy encoding too
    sep="") 
  if event == 'line':
    try:
      if frame.f_locals['cmd'] == 'delete':
        print("> deleting...\n")
        del frame.f_trace
      elif frame.f_locals['cmd'] == 'setNone':
        print("> Wiping...\n")
        frame.f_trace = None
    except:
      # suppress events having {'input':'delete', ...}
      # print("Other 'line' event:", frame.f_locals)   
      pass
    return None # or function() I think?
  return tracer
  
def traceMe(cmd):
  # Each of these causes 3 extra events doing encoding;
  # Comment @4-9 to suppress or add frame.f_locals to see.
OUTPUT