If I need a for loop in Python:
for i in range(1,42):
print "spam"
but don't use the i for anything, pylint complains about the unused variable. How should I handle this? I know you can do this:
for dummy_index in range(1,42):
print "spam"
but doing this seems quite strange to me. Is there a better way?
I'm quite new to Python, so forgive me if I'm missing something obvious.
for _ in range(1,42):
print "spam"
foo, _ = func_returning_tuple() Having said this, I would prefer _i over plain _.
_ for this when also using the gettext library (or thinking you might use it in the future) will cause problems. Gettext uses _ as a i18n translating function (_("Translate this text")), but after the above loop _ would suddenly be 41 instead and the next invocation would raise an exception.
i, or use a prefix, probably the default _ (less distracting than dummy).There is no "natural" way to loop n times without a counter variable in Python, and you should not resort to ugly hacks just to silence code analyzers.
In your case I would suggest one of the following:
i, that are usually only used in for loops anyway._ (it's less distracting than dummy)
According to pylint documentation:
--dummy-variables-rgx=
A regular expression matching names used for dummy variables (i.e.
not used). [current: _|dummy]
In other words, if the name of the variable starts with an underscore, or with the letters dummy, pylint would not complain about the variable being unused:
for dummy in range(1, 42):
print "spam"
Usually you can work around it, just like this in your case:
>>> print "spam\n"*len(range(1,42))
3 Simple Reasons
for loop. index[1] to index[2] just by adding if index[1]is done. return index[]+1.for loop and is not efficient in long programs.
_ordummyprefix, or decide on a different scheme and set PyLint's--dummy-variables-rgxoption accordingly (e.g.,unused_).forstatement, the only dummy thing around is pylint itself. I'd advise placing this as a bug report in the pylint project.