wsgirouter3

Small opinionated WSGI request dispatcher. Influenced by Flask.

Works using path segments instead of more common regex matching (RFC 3986 path segment parameters are not supported) https://datatracker.ietf.org/doc/html/rfc3986#section-3.3

Path variables are by default defined using RFC 6570 level 1 https://datatracker.ietf.org/doc/html/rfc6570#section-1.2 Start and optional end markers are customizable. Path variable types are defined using python typing information. Customizable, types supported out-of-box: bool, int, str, uuid.UUID.

WSGI environ wrapper can passed to handler if there is parameter with type Request. No global variables/threadlocals. Request body and query string binding is also supported, using generic types Body and Query.

Supports overlapping path segments: zero or more literal segments can overlap with one parameter definition. Parameters of different type and/or name in same position are not supported. Literal segment takes precedence.

Route decorators for HTTP methods DELETE, GET, PATCH, POST, PUT.

Response compression. By default enabled for application/json. Configurable compression level.

@router.get('/abc/literal')
def literal():
    pass

@router.get('/abc/{variable}')
def parameterized(variable: str):
    pass

Multiple routes can point to same handler:

@router.get('/abc', defaults={'variable': None})
@router.get('/abc/{variable}')
def with_optional_parameter(variable: Optional[str]):
    pass

Content negotiation:

@router.get('/get', produces='application/json')
def get() -> dict:
    return {'field': 'value'}

@router.post('/post', consumes='application/json')
def post_with_json(req: Request) -> Tuple[int]:
    data = req.json
    return 204,

Query string and request body binding:

@router.get('/get', produces='application/json')
def get(query: Query[dict]) -> dict:
    return query

@router.post('/post', consumes='application/json')
def post_with_json(data: Body[dict]) -> Tuple[int]:
    # do something with data
    return 204,

Handler return type handling:

Type	Description
tuple	shortcut for returning status code and optional result + headers
None	allowed for status codes which have no content
dict	application/json
str	defined by optional Content-Type header. When header is missing, taken from config.default_str_content_type, by default text/plain;charset=utf-8
bytes	defined by required Content-Type header
dataclass	application/json, but overridable by custom result handler
typing.GeneratorType	passed as is

Cache control for responses:

@router.get('/no-store', cache_control=CacheControl.no_store)
def no_store() -> dict:
    return {'a': 1}

@router.get('/store', cache_control=CacheControl.of(max_age=600, private=False))
def store() -> dict:
    return {'a': 1}

Configuration checklist

WsgiAppConfig class

Task	Action
Want to use another json library or configure value types serialized / deserialized	Override json_serializer / json_deserializer
Change maximum length of accepted request body	Set value of max_request_content_length
Change default content type for str returned	Change value of default_str_content_type
Add authorization	Set before_request hook handler, use route options to define roles. See sample
Handle more return types	Add entry of tuple[matcher, handler] to result_converters or override custom_result_handler
Validate/convert query string and request body	Use Query and Body generics with value class in handler and override binder
Customize error handling	Override error_handler
Disable response compression	set compress_level to 0
Enable response compression for more cases	Update compress_content_types and/or override can_compress_result
Configure compression level	Set value of compress_level (0-9 or -1, see zlib documentation)

PathRouter class

Task	Action
Change parameter markers	Change value of path_parameter_start and path_parameter_end
Add new path parameter type	Add new class inherited from PathParameter into parameter_types

Installation

$ pip install wsgirouter3