Question

Python is all about writing beautiful code. So, I was running pylint to check the “beautifulness” of my code, when I bump into something:

Unused variable ‘myvar1’

From this part of my code:

for myvar1, myvar2 in mylist:
    # Do stuff just using myvar2

mylist is a list of tuples, so I’m unwrapping the tuples into two variables (myvar1 and myvar2). I’m defining those two variables just to unwrap the second one, because I don’t need the other.

So, here’s my question: Is there a way to tell the interpreter to unwrap the tuple, but not assing the first part (for example). In some other languages you can do something like:

for _, myvar in mylist:
    # Do stuff with myvar

or

for *, myvar in mylist:
    # Do stuff with myvar

That means: I don’t care about the first part of the tuple, I just need the second one.

NOTE: I know that this could be an option for what I’m asking:

for mytuple in mylist:
    # Do stuff with mytuple[1]

But that’s by far less readable.

Answer 1

In addition to @RaymondHettinger’s answer: Pylint also does not complain about unused variables if their names start with a single underscore. This means that you can use:

for _myvar1, myvar2 in mylist:

getting the best of both worlds:

• no Pylint warning,
• and information about the record structure

This works for function / method prototypes too and avoids warnings about unused parameters, which you can often get when deriving from a base class in an OO framework.