Resolve various pylint warnings

This branch updates the code to resolve a range of pylint warnings - specifically:

• redefined-builtin
• pointless-statement
• unused-private-member
• unused-argument
• anomalous-backslash-in-string
• unreachable
• unused-variable
• unused-import
• dangerous-default-value
• useless-parent-delegation
• redefined-outer-name

Some other warnings are left disabled for now - they would either take too long to address now, or addressing them is of debatable benefit.