C_StyleParentheses.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>
<overview>
<p>Python is designed to be more readable, at least for Western readers, than languages in the C family.
This is achieved, in part, by using English language keywords and more familiar punctuation.
Top level expressions are thus bracketed by the keyword and either a colon or new line, which can be more
easily picked put by eye than parentheses.
</p>

<p>Using superfluous parentheses can impair this readability by making the code harder to scan and parse by eye.
Parentheses often serve as a visual clue for more complex expressions, and adding them unnecessarily can be distracting.
</p>

<p>One notable exception to this rule is when an expression has to span multiple lines. In which case, using of parentheses is
preferred to using a back slash for line continuation.
</p>

</overview>
<recommendation>

<p>
Remove the unnecessary parentheses.
</p>

</recommendation>
<example>
<p>In the first of the two examples, most of the expressions are wrapped in parentheses.
This is harder to read than the second example, especially to a programmer more familiar with Python than with C or Java.

</p><sample src="C_StyleParentheses.py" />

</example>
<references>

<li>Python Language Reference: <a href="https://docs.python.org/2/reference/grammar.html">Full grammar specification</a>.</li>
<li>Google Python Style Guide: <a href="https://google.github.io/styleguide/pyguide.html#Parentheses">Use parentheses sparingly</a>.</li>
<li>Python PEP Index: <a href="http://legacy.python.org/dev/peps/pep-0008/">PEP 8</a>.</li>


</references>
</qhelp>