NO_PROXY Does Not Erase an Explicit Requests Route
Distinguish suppressing environment proxy discovery from removing a proxy deliberately supplied in a Requests mapping.
When the application supplies Requests with its proxy policy, give a direct exception to that same policy. For an existing Session and a narrowly scoped call:
direct_routes = {'http': '', 'https': ''}
response = session.get(url, proxies=direct_routes, timeout=15)The explicit empty values select direct routing for the relevant schemes. Inspect the actual call and Session defaults for more-specific host keys too; a scheme-only override does not remove a separate host-specific route.
Why did adding the host to NO_PROXY leave the explicit proxy in place? Requests 2.34.2's resolver copies the provided mapping and considers whether the environment should fill missing entries. A bypass match can suppress that discovery without deleting a route the application already supplied.
Check the mapping used by this operation before adding exceptions at another layer. Keep TLS verification enabled on the direct route. If a redirect changes the route again, inspect None versus empty proxy values across that transition. A certificate error there is evidence about destination trust on that path, which is separate from whether a proxy was selected.