catchmrbharath/sympy — comment on commit 471bb79b5c3822341e6e1c740ecd17fbac51a525
File:  line 0
By pernici:

Usually examples in docstrings are simple, so that one can easily verify them by hand, to confirm understanding of the use
of the method; therefore I suggest to put something like

```
>>> Permutation([3, 2, 1, 0]).inversions()
6
```