# coding: utf-8
"""
This Listener simply prints to stdout / the terminal or a file.
"""
from __future__ import print_function, absolute_import
import logging
from can.listener import Listener
from .generic import BaseIOHandler
log = logging.getLogger('can.io.printer')
[docs]class Printer(BaseIOHandler, Listener):
"""
The Printer class is a subclass of :class:`~can.Listener` which simply prints
any messages it receives to the terminal (stdout). A message is turned into a
string using :meth:`~can.Message.__str__`.
:attr bool write_to_file: `True` iff this instance prints to a file instead of
standard out
"""
def __init__(self, file=None):
"""
:param file: an optional path-like object or as file-like object to "print"
to instead of writing to standard out (stdout)
If this is a file-like object, is has to opened in text
write mode, not binary write mode.
"""
self.write_to_file = file is not None
super(Printer, self).__init__(file, mode='w')
[docs] def on_message_received(self, msg):
if self.write_to_file:
self.file.write(str(msg) + '\n')
else:
print(msg)