pep cleanup for words/morphism.py

[fchapoton]

also fixing some lgtm warnings

and some code details

CC: @tscrim @kwankyu @kliem @slel

Component: combinatorics

Author: Frédéric Chapoton

Branch/Commit: f4e7ee1

Reviewer: David Coudert

Issue created by migration from https://trac.sagemath.org/ticket/33993

[fchapoton]

Branch: u/chapoton/33993

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

f4e7ee1

full pycodestyle cleanup for words/morphism.py

[sagetrac-git]

Commit: f4e7ee1

[fchapoton]

comment:3

green bot, so please review

[dcoudert]

comment:4

Can you explain this change

             if isinstance(w, Iterable):
-                datatype = 'iter'
+                pass

[fchapoton]

comment:5

variable non utilisée

[dcoudert]

Reviewer: David Coudert

[dcoudert]

comment:6

C'était mon impression, mais j'avais un petit doute. Merci.

LGTM.

[vbraun]

Changed branch from u/chapoton/33993 to f4e7ee1