AttributeError: module 'html' has no attribute 'parser'

What it does

Checks for accesses of submodules that might not've been imported.

Why is this bad?

When module a has a submodule b, import a isn't generally enough to let you access a.b. You either need to explicitly import a.b, or else you need the __init__.py file of a to include from . import b. Without one of those, a.b is an AttributeError.

Examples

import html

# AttributeError: module 'html' has no attribute 'parser'
html.parser  # error