5 ms·

Agreed! In fact, I think this makes it so all print() calls by default write to stderr: >>> import sys, functools, builtins >>> real_print = print >>> b

Agreed! In fact, I think this makes it so all print() calls by default write to stderr: >>> import sys, functools, builtins >>> real_print = print >>> builtins.print = functools.partial(real_print, file=sys.stderr) >>> print("Hello") Hello

abdusco 4y ago
Or use logging module as you should, which prints to stderr by default. import logging logging.basicConfig() logging.info('something happened')
- prirun 4y ago
  The problem for me with logging is that it's slow for production code: Python 2.7.15 Linux (logging is 60x slower): [root@hbtest ~]# py -m timeit -s 'import logging' "logging.info('something happened')" 1000000 loops, best of 3: 1.31 usec per loop [root@hbtest ~]# py -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'" 10000000 loops, best of 3: 0.0216 usec per loop Python 2.7.15 OSX (logging is 71x slower): $ py -m timeit -s 'import logging' "logging.info('something happened')" 1000000 loops, best of 3: 0.925 usec per loop [jim@mbp hbrel]$ py -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'" 100000000 loops, best of 3: 0.013 usec per loop Python 3.6.8 Linux (logging is 99x slower): [root@hbtest ~]# python3 -m timeit -s 'import logging' "logging.info('something happened')" 1000000 loops, best of 3: 1.62 usec per loop [root@hbtest ~]# python3 -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'" 100000000 loops, best of 3: 0.0163 usec per loop And, as usual, Python 3 is 25% slower than Python 2 for the logging case (but 2x faster for the noop if debug case). I hope the recent efforts to increase Python 3 performance are successful.
  - mixmastamyk 4y ago
    Microseconds are not important unless in a very tight loop. Avoid there and/or make a shortcut beforehand.
    - eesmith 4y ago
      And we don't know why tus666 wants to print to stderr, nor what the issue was with Python, so this digression seems built on sand.

abdusco 4y ago

Or use logging module as you should, which prints to stderr by default. import logging logging.basicConfig() logging.info('something happened')

prirun 4y ago
The problem for me with logging is that it's slow for production code: Python 2.7.15 Linux (logging is 60x slower): [root@hbtest ~]# py -m timeit -s 'import logging' "logging.info('something happened')" 1000000 loops, best of 3: 1.31 usec per loop [root@hbtest ~]# py -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'" 10000000 loops, best of 3: 0.0216 usec per loop Python 2.7.15 OSX (logging is 71x slower): $ py -m timeit -s 'import logging' "logging.info('something happened')" 1000000 loops, best of 3: 0.925 usec per loop [jim@mbp hbrel]$ py -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'" 100000000 loops, best of 3: 0.013 usec per loop Python 3.6.8 Linux (logging is 99x slower): [root@hbtest ~]# python3 -m timeit -s 'import logging' "logging.info('something happened')" 1000000 loops, best of 3: 1.62 usec per loop [root@hbtest ~]# python3 -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'" 100000000 loops, best of 3: 0.0163 usec per loop And, as usual, Python 3 is 25% slower than Python 2 for the logging case (but 2x faster for the noop if debug case). I hope the recent efforts to increase Python 3 performance are successful.
- mixmastamyk 4y ago
  Microseconds are not important unless in a very tight loop. Avoid there and/or make a shortcut beforehand.
  - eesmith 4y ago
    And we don't know why tus666 wants to print to stderr, nor what the issue was with Python, so this digression seems built on sand.