There are several ways to write to stderr:
# Note: this first one does not work in Python 3
print >> sys.stderr, "spam"
sys.stderr.write("spam\n")
os.write(2, b"spam\n")
from __future__ import print_function
print("spam", file=sys.stderr)
That seems to contradict zen of Python #13 †, so what's the difference here and are there any advantages or disadvantages to one way or the other? Which way should be used?
† There should be one — and preferably only one — obvious way to do it.
I found this to be the only one short + flexible + portable + readable:
from __future__ import print_function
import sys
def eprint(*args, **kwargs):
print(*args, file=sys.stderr, **kwargs)
The function eprint
can be used in the same way as the standard print
function:
>>> print("Test")
Test
>>> eprint("Test")
Test
>>> eprint("foo", "bar", "baz", sep="---")
foo---bar---baz