`abs()` is a built-in function in Python 3, to compute the absolute value of any number. The absolute value of a number "means only how far a number is from 0" <sup>1</sup> It takes one argument `x`. The argument can even be a <ahref='https://docs.python.org/3.0/library/cmath.html'target='_blank'rel='nofollow'>complex number</a>, or a <ahref='https://en.wikipedia.org/wiki/Expression_(mathematics)'target='_blank'rel='nofollow'>mathematical expression</a>.
The return value would be a positive number or zero. Even if a complex number is passed, it would return its magnitude, computed as per complex number algebra.
+ A complex number is passed - It would return its <ahref='http://www.mathcentre.ac.uk/resources/sigma%20complex%20number%20leaflets/sigma-complex9-2009-1.pdf'target='_blank'rel='nofollow'>modulus</a> i.e., magnitude, computed as per complex number algebra.
+ A mathematical expression is passed - It would return its `|result|`, computed as per <ahref ='https://en.wikipedia.org/wiki/Order_of_operations'target='_blank'rel='nofollow'> BODMAS </a> rule.