Correct way to implement placeholder variables (PEP8)
<p>I run into the problem of needing placeholder variables a lot. I try to code according to PEP8, and always follow it, also i am using PyCharm which notifies me about mistakes. Currently i use <code>_</code> as i have seen this in a lot of online codes, but i guess it is wrong as i still got the warnings. What is the correct way of doing this?</p>

<p>Some examples:</p>

<p>I need a list (with given length) of tuples where each tuple is (0, None):</p>

<pre><code>bound = [(0, None) for _ in ENERGY_ATTRIBUTES]
</code></pre>

<p>An unordered multiprocess where the function does not return anything</p>

<pre><code>for _ in p.imap_unordered(partial(read_energies, round=i), PEPTIDE_KD.keys()):
    pass
</code></pre>

<p>Also tried </p>

<pre><code>_ = [_ for _ in p.imap_unordered(partial(read_energies, round=i), PEPTIDE_KD.keys())]
</code></pre>

<p>Same warnings.</p>

<p>Ignore the warnings if you know they are harmless. They are warnings, not errors or exceptions. If you know what you are doing, ignore or suppress the warnings!</p>

python python-3.x pep8