The goal of this ticket is to clean up of the code in sage/rings/number_field/maps.py, which contains several unnecessary attributes and conversions. One motivation for this is to simplify work on #252.

There are no changes in functionality. The total running time of the doctests in sage/rings/number_field does not increase and even appears to decrease slightly.

Component: number fields

Author: Peter Bruin

Branch/Commit: 195d3d2

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/18727