tha-req-runner

A small Python library that provides a thread-safe HTTP session with automatic retries and a normalized response parser. Supports both requests (default) and httpx backends. Intended as the HTTP transport layer for other tha-* runners.

Install

pip install tha-req-runner           # requests backend (default)
pip install tha-req-runner[httpx]    # adds httpx backend support

Quick start

from tha_req_runner import ThaReq

# requests backend (default)
req = ThaReq()
session = req.get_session()

# httpx backend
req = ThaReq(backend="httpx")
client = req.get_session()

# safe_call wraps the try/except for you — same API regardless of backend
result = req.safe_call(session.get, "https://api.example.com/students", params={"limit": 100})
# {"status": None, "code": 200, "data": [...], "message": None, "raw_response": <Response>}

# network errors return the same shape — no try/except needed
result = req.safe_call(session.get, "https://unreachable.example.com")
# {"status": "error", "code": None, "data": None, "message": "Connection refused", "raw_response": None}

Response dict

Every call returns the same shape whether it succeeded or raised:

safe_call automatically calls raise_for_status(), so 4xx/5xx responses are treated as errors:

# 200 → success path
{"status": None, "code": 200, "data": {"id": 1}, "message": None, "raw_response": <Response>}

# 422 with JSON error body → error path, data preserved
{"status": "error", "code": 422, "data": {"detail": "field required"}, "message": "422 Unprocessable Entity", "raw_response": <Response>}

# network error → no code or data
{"status": "error", "code": None, "data": None, "message": "Connection refused", "raw_response": None}

API

ThaReq

ThaReq(*, backend: Literal["requests", "httpx"] = "requests")

backend="httpx" requires pip install tha-req-runner[httpx].

req.get_session()

req.get_session(
    *,
    status_forcelist: tuple[int, ...] = (500, 502, 503, 504),  # requests only
    allowed_methods: Collection[str] | None = None,             # requests only
    headers: dict[str, str] | None = None,
    timeout: float = 30,
) -> requests.Session | httpx.Client

Returns a session configured with automatic retries. Config is applied only on the first call per thread — subsequent calls on the same thread return the cached session regardless of args. Two ThaReq instances never share a session.

allowed_methods=None uses urllib3's safe-method default, which excludes POST. To retry POST (e.g. token endpoints):

session = req.get_session(
    status_forcelist=(429, 500, 502, 503, 504),
    allowed_methods=frozenset(["GET", "POST"]),
)

httpx note: status_forcelist and allowed_methods are ignored for the httpx backend. httpx retry is connection-level only (no status-based retry).

req.reset_session() / req.close_session()

Closes and discards the current thread's session. The next get_session() call creates a fresh one. Useful when auth tokens rotate or a session enters a bad state. Both methods are equivalent.

ThaReq.parse_response()

ThaReq.parse_response(result) -> dict[str, Any]

Normalizes a response object or a caught exception into a consistent dict. Works with both requests.Response and httpx.Response. Also callable as an instance method.

req.safe_call()

req.safe_call(fn, *args, **kwargs) -> dict[str, Any]

Calls fn(*args, **kwargs), calls raise_for_status() on the response, catches any exception, and returns a normalized response dict. Automatically injects the session timeout unless the caller provides one. JSON error bodies from 4xx/5xx responses are preserved in data.

result = req.safe_call(session.get, url, params={"limit": 100})
result = req.safe_call(session.post, token_url, data={"grant_type": "client_credentials"})
result = req.safe_call(session.get, url, timeout=5)  # override per-call

Session and retries

• Thread-safe: each thread gets its own session via threading.local on the instance
• Retry defaults: total=3, backoff_factor=0.5 (delays: 0.5s → 1s → 2s)
• Retry statuses: 500, 502, 503, 504 by default (requests backend only)
• POST not retried by default — pass allowed_methods explicitly to enable it (requests backend only)
• Default timeout: 30s, injected automatically by safe_call
• Sessions are reused across calls on the same thread

Backend comparison

Alternatives

This library is intentionally limited in scope — it provides a thin, thread-safe wrapper around requests or httpx with automatic retries and a normalized response dict. If you need more control:

• httpx — modern HTTP client with async support and HTTP/2 built in; use directly if you don't need the session wrapper or normalized response shape
• requests — the underlying sync HTTP library; sufficient on its own for simple, single-threaded use
• tenacity — standalone retry library that wraps any function; more configurable than urllib3's built-in retry for complex retry strategies

Choose this library when you need thread-safe sessions, automatic retries, and a normalized response dict that fits the tha-* error pattern — none of the alternatives give you all three out of the box.

Used by

• tha-edfi-runner — uses ThaReq as its HTTP transport layer

License

MIT