Fix certbot.compat.os docs (#8209)

* Don't document stdlib os.

* Move isort out of docstring.

* fix os import

* fix comment length

certbot/certbot/compat/os.py

@@ -3,8 +3,11 @@ This compat modules is a wrapper of the core os module that forbids usage of spe
 (e.g. chown, chmod, getuid) that would be harmful to the Windows file security model of Certbot.
 This module is intended to replace standard os module throughout certbot projects (except acme).
 
-isort:skip_file
+This module has the same API as the os module in the Python standard library
+except for the functions defined below.
+
 """
+# isort:skip_file
 # pylint: disable=function-redefined
 from __future__ import absolute_import
 
@@ -21,10 +24,13 @@ import os as std_os  # pylint: disable=os-module-forbidden
 import sys as std_sys
 
 ourselves = std_sys.modules[__name__]
+# Adding all of stdlib os to this module confuses Sphinx so we skip this when
+# building the documentation.
+if not std_os.environ.get("CERTBOT_DOCS") == "1":
     for attribute in dir(std_os):
-    # Check if the attribute does not already exist in our module. It could be internal attributes
+        # Check if the attribute does not already exist in our module. It could
-    # of the module (__name__, __doc__), or attributes from standard os already imported with
+        # be internal attributes of the module (__name__, __doc__), or
-    # `from os import *`.
+        # attributes from standard os already imported with `from os import *`.
         if not hasattr(ourselves, attribute):
             setattr(ourselves, attribute, getattr(std_os, attribute))