Quickly build API services to expose functionality in Python.
KwikAPI
lets a python developer focus on writing their logic and not worrying about the service like funtionality (There are numerous things to address like serialization protocols, bulk requests, versioning, grouping API calls into logical sets etc).
$ sudo pip3 install kwikapi
Here is an example of how to use KwikAPI
to expose Calc
as a service. We will use KwikAPI
with the tornado
webserver in this example.
To use KwikAPI with tornado install
sudo pip3 install kwikapi[tornado]
import tornado.ioloop
import tornado.web
from kwikapi.tornado import RequestHandler
from kwikapi import API
# Core logic that you want to expose as a service
class Calc(object):
def add(self, a: int, b: int) -> int:
return a + b
def subtract(self, a: int, b: int) -> int:
return a - b
# Standard boilerplate code to define the service. This
# code will remain more or less the same size regardless
# of how big the code/complexity of `BaseCalc` above is.
# Register BaseCalc with KwikAPI
api = API()
api.register(Calc(), 'v1')
# Passing RequestHandler to the KwikAPI
def make_app():
return tornado.web.Application([
(r'^/api/.*', RequestHandler, dict(api=api)),
])
# Starting the application
if __name__ == "__main__":
app = make_app()
app.listen(8888)
tornado.ioloop.IOLoop.current().start()
Making an API request
$ wget http://localhost:8888/api/v1/add?a=10&b=20
$ wget http://localhost:8888/api/v1/subtract?a=10&b=20
For more examples of KwikAPI with Tornado go through this link and with Django go through this link
To demonstrate the various features of KwikAPI
and also to use the same examples
as living documentation and test cases, we use MockRequest
so we don't need
tornado
or django
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler
>>> class Calc(object):
... # Type information must be specified
... def add(self, a: int, b: int) -> int:
... return a + b
>>> api = API()
>>> api.register(Calc(), "v1") # `v1` is the version of this example
>>> req = MockRequest(url="/api/v1/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
- Versioning support
- Type checking
- Namespace
- Customizing request and response
- Streaming
- Protocol handling
- API Doc
- Bulk request handling
- KwikAPI Client
- Authentication
Versioning support will be used if user wants different versions of functionality with slightly changed behaviour.
Specifying the version is mandatory for every class.
We can register the same class with different versions (for testing here)
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler
>>> class Calc(object):
... def add(self, a: int, b: int) -> int:
... return a + b
>>> api = API()
>>> api.register(Calc(), "v1")
>>> api.register(Calc(), "v2")
>>> req = MockRequest(url="/api/v1/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
>>> req = MockRequest(url="/api/v2/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
We can register different classes with different versions
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler
>>> class Calc(object):
... def add(self, a: int, b: int) -> int:
... return a + b
>>> class ConcStr(object):
... def add(self, a: str, b: str) -> str:
... return a+b
>>> api = API()
>>> api.register(Calc(), "v1")
>>> api.register(ConcStr(), "v2")
>>> req = MockRequest(url="/api/v1/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
>>> req = MockRequest(url="/api/v2/add?a=in&b=dia")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
'india'
>>> res['success']
True
We can specify the default version so that when you don't mention version in the request URL then default version will be used.
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler
>>> class Calc(object):
... # Type information must be specified
... def add(self, a: int, b: int) -> int:
... return a + b
>>> api = API(default_version='v1')
>>> api.register(Calc(), "v1")
>>> req = MockRequest(url="/api/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
Specifying type for parameters and for return value will exactly meet the functionality. This is mandatory in KwikAPI (If the method don't return anything then None
should be specified as return type)
>>> class Calc(object):
... # Type information must be specified
... def add(self, a: int, b: int) -> int:
... return a + b
... def sub(self, a: int, b: int) -> None:
... c = a - b
KwikAPI supports builtin types and types from typing such as Union, List, Tuple, Dict, Generator, Any and so on.
Here are some examples of how to use type hints.
- If a single argument expects two or more types then Union can be used
>>> from typing import Union
>>> class Calc(object):
... def add(self, a: Union[int, float], b: int) -> Union[int, float]:
... return a + b
- If we want to pass same type of values in list then List type can be used. If the list values are different types then builtin list can be used as type annotation
>>> from typing import List
>>> class Calc(object):
... def add(self, a: List[str], b: list) -> list:
... return a + b
- If we want to pass same type of keys and same type of values in dictionary then Dict type can be used. If the dictionary keys and values are different types then builtin dict can be used as type annotation
>>> from typing import Dict
>>> class Calc(object):
... def add(self, a: Dict[str, int], b: dict) -> dict:
... return a.update(b)
- For cheking values inside tuple then we can use Tuple from typing other wise we can use builtin tuple
>>> from typing import Tuple
>>> class Calc(object):
... def add(self, a: Tuple[str, int, float], b: tuple) -> tuple:
... return a + b
- If the method contains more than one return value then we can mention types in square brackets
>>> from typing import List
>>> class Calc(object):
... def add(self, a: int, b: int) -> [int, int]:
... return a, b
- If request or response contains stream data then we can use Generator
>>> from typing import Generator
>>> class Calc(object):
... def add(self, a: Generator) -> int:
... _sum = 0
... for i in a:
... _sum += i
... return _sum
- If we don't need to bother about type checking then we can simply use Any from typing
>>> from typing import Any
>>> class Calc(object):
... def add(self, a: Any, b: Any) -> Any:
... return a, b
Register methods with different namespaces
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler
>>> class Calc(object):
... def add(self, a: int, b: int) -> int:
... return a + b
>>> class ConcStr(object):
... def add(self, a: str, b: str) -> str:
... return a+b
>>> api = API(default_version="v1")
>>> api.register(Calc(), "v1", "Calc")
>>> api.register(ConcStr(), "v1", "Calc/ConcStr")
>>> req = MockRequest(url="/api/v1/Calc/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
>>> req = MockRequest(url="/api/v1/Calc/ConcStr/add?a=in&b=dia")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
'india'
>>> res['success']
True
Register same methods with same version with different namespaces
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler, Request
>>> class Calc(object):
... def add(self, req: Request, a: int, b: int) -> int:
... return a + b
>>> class CalcScintific(object):
... def add(self, req: Request, a: int, b: int) -> int:
... return a + b + 10
>>> api = API()
>>> api.register(Calc(), "v1")
>>> api.register(CalcScintific(), "v1", "scintific")
>>> req = MockRequest(url="/api/v1/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
>>> req = MockRequest(url="/api/v1/scintific/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
40
>>> res['success']
True
We can also register same methods with same namespace with different versions
User can change the response if he wants it
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler, Request
>>> class Calc(object):
... # Type information must be specified
... def add(self, req: Request, a: int, b: int) -> int:
... req.response.headers['something'] = 'something'
... return a + b
>>> api = API()
>>> api.register(Calc(), "v1")
>>> req = MockRequest(url="/api/v1/add?a=10&b=20")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
KwikAPI supports request and response Streaming
class MyAPI(object):
# Streaming response
def streaming_response_test(self, num: int) -> Generator:
for i in range(num):
yield {i: i}
# Streaming request
def streaming_request_test(self, numbers: Generator) -> int:
_sum = 0
for i in numbers:
_sum += i
return _sum
$ wget "http://localhost:8888/api/v1/streaming_response_test" --post-data '{"a": 10}'
$ wget "http://localhost:8888/api/v1/streaming_request_test" --post-file /tmp/numbers
/tmp/numbers
0
1
2
3
...
...
1000000
KwikAPI supports JSON, Messagepack, Pickle and Numpy protocols
# Users can define their own protocols and can register with KwikAPI
>>> import json
>>> from kwikapi import API, MockRequest, BaseRequestHandler, Request, BaseProtocol
>>> class Calc(object):
... # Type information must be specified
... def add(self, req: Request, a: int, b: int) -> int:
... return a + b
>>> class CustomProtocol(BaseProtocol):
... @staticmethod
... def get_name():
... return 'custom'
... @staticmethod
... def serialize(data):
... return json.dumps(data)
... @staticmethod
... def deserialize(data):
... return json.loads(data)
... @classmethod
... def deserialize_stream(cls, data):
... for line in data:
... yield cls.deserialize(line.decode('utf8'))
... @staticmethod
... def get_record_separator():
... return '\n'
... @staticmethod
... def get_mime_type():
... return 'application/json'
>>> api = API()
>>> api.register(Calc(), "v1")
>>> base = BaseRequestHandler(api)
>>> base.register_protocol(CustomProtocol())
>>> req = MockRequest(url="/api/v1/add?a=10&b=20")
>>> res = json.loads(base.handle_request(req).decode('utf-8'))
>>> res['result']
30
>>> res['success']
True
>>> import msgpack
>>> from kwikapi import API, MockRequest, BaseRequestHandler
>>> class Calc(object):
... # Type information must be specified
... def add(self, a: int, b: int) -> int:
... return a + b
>>> api = API()
>>> api.register(Calc(), "v1") # `v1` is the version of this example
>>> base = BaseRequestHandler(api, default_protocol='messagepack')
>>> req = MockRequest(url="/api/v1/add?a=10&b=20")
>>> res = msgpack.unpackb(base.handle_request(req))
>>> res[b'result']
30
>>> res[b'success']
True
If user wants to use specific protocol with specific request then he should specify the protocol in headers ex:
$ wget "http://localhost:8888/api/v1/add" --header="X-KwikAPI-Protocol: messagepack" --post-file /tmp/data.msgpack
$ wget "http://localhost:8888/api/v1/subtract" --header="X-KwikAPI-Protocol: json" --post-data '{"a": 10, "b": 20}'
$ wget "http://localhost:8888/api/v1/add" --header="X-KwikAPI-Protocol: pickle" --post-file /tmp/data.pickle
$ wget "http://localhost:8888/api/v1/add" --header="X-KwikAPI-Protocol: numpy" --post-file /tmp/data.numpy
Using API Doc we can look at what are the all API methods available
To see available API methods the URL will be http://localhost:8888/api/v1/apidoc for default version
To check API methods under specific version we can provide URL as http://localhost:8888/api/v1/apidoc?version=<-version->
To check API methods under specific version and namespace we can provide URL as http://localhost:8888/api/v1/apidoc?version=<-version->&namespace=<-namespace->
>>> import json
>>> from pprint import pprint
>>> from kwikapi import API, MockRequest, BaseRequestHandler
>>> class Calc(object):
... def add(self, a: int, b: int) -> int:
... return a + b
>>> api = API()
>>> api.register(Calc(), "v1", "calc")
>>> req = MockRequest(url="/api/v1/apidoc")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> pprint(res['result'])
{'namespace': {"('v1', 'calc')": {'add': {'doc': None,
'gives_stream': False,
'params': {'a': {'default': None,
'required': True,
'type': 'int'},
'b': {'default': None,
'required': True,
'type': 'int'}},
'return_type': 'int'}}},
'version': {'v1': {'add': {'doc': None,
'gives_stream': False,
'params': {'a': {'default': None,
'required': True,
'type': 'int'},
'b': {'default': None,
'required': True,
'type': 'int'}},
'return_type': 'int'},
'apidoc': {'doc': None,
'gives_stream': False,
'params': {'namespace': {'default': None,
'required': False,
'type': 'str'},
'version': {'default': None,
'required': False,
'type': 'str'}},
'return_type': 'dict'}}}}
>>> res['success']
True
>>> req = MockRequest(url="/api/v1/apidoc?version=v1&namespace=calc")
>>> res = json.loads(BaseRequestHandler(api).handle_request(req).decode('utf-8'))
>>> pprint(res['result'])
{'add': {'doc': None,
'gives_stream': False,
'params': {'a': {'default': None, 'required': True, 'type': 'int'},
'b': {'default': None, 'required': True, 'type': 'int'}},
'return_type': 'int'}}
>>> res['success']
True
It will be very convenient if the user has facility to make bulk requests. When making a large number of requests, the overhead of network latency and HTTP request/response processing can slow down the operation. It is convenient and necessary to have a mechanism to sent a set of requests in bulk.
KwikAPI
provides client tool which will help in making calls to server. The KwikAPI Client
will take
care of serialization and deserialization of the data.
Usage:
from kwikapi import Client
c = Client('http://localhost:8818/api/', version='v1')
# `add` is the api method
print(c.add(a=10, b=10))
# Namespace will be used with Client object
print(c.namespace.add(a=10, b=10))
# Parameters can be changed that are passed to the Client object
print(c(version='v2', protocol='pickle').namespace.add(a=10, b=10))
Streaming response is handled by passing the parameter stream
as True.
c = Client('http://localhost:8818/api/', version='v1')
res = c(stream=True).add(a=10, b=10)
# You will get generator object on stream True
for r in res:
print(r)
KwikAPI supports Basic
and Bearer
authentication.
Basic authentication:
Setting up authentication at server side
import tornado.ioloop
import tornado.web
from kwikapi.tornado import RequestHandler
from kwikapi import API, Request, BasicServerAuthenticator
class Calc(object):
def add(self, req: Request, a: int, b: int) -> int:
if not req.auth.is_authenticated:
raise Exception("No auth") # Or your logic
return a + b
user_store = dict(johndoe=dict(password='password'))
auth = BasicServerAuthenticator(user_store=user_store)
api = API(auth=auth)
api.register(Calc(), 'v1')
def make_app():
return tornado.web.Application([
(r'^/api/.*', RequestHandler, dict(api=api)),
])
if __name__ == "__main__":
app = make_app()
app.listen(8818)
tornado.ioloop.IOLoop.current().start()
Using authentication at client side.
from kwikapi import Client, BasicClientAuthenticator
auth = BasicClientAuthenticator(username='johndoe', password='password')
c = Client('http://localhost:8818/api/', version='v1', auth=auth, protocol='json')
print(c.add(a=10, b=10))
Bearer Authentication
Setting up authentication at server side
import tornado.ioloop
import tornado.web
from kwikapi.tornado import RequestHandler
from kwikapi import API, BearerServerAuthenticator, Request
class Calc(object):
def add(self, req: Request, a: int, b: int) -> int:
if not req.auth.is_authenticated:
raise Exception("No auth")
return a + b
tokstore = dict(
key1 = dict(user='blah'),
key2 = dict(user='blah1'),
)
auth = BearerServerAuthenticator(token_store=tokstore)
api = API(auth=auth)
api.register(Calc(), 'v1')
def make_app():
return tornado.web.Application([
(r'^/api/.*', RequestHandler, dict(api=api)),
])
if __name__ == "__main__":
app = make_app()
app.listen(8818)
tornado.ioloop.IOLoop.current().start()
Using authentication at client side.
from kwikapi import Client, BearerClientAuthenticator
auth = BearerClientAuthenticator('key2')
c = Client('http://localhost:8818/api/', version='v1', auth=auth, protocol='json')
print(c.add(a=10, b=10))
If you don't want to use KwikAPI client then you have to pass the authentication deatails through headers.
- Example for passing authentication details in Base Authentication.
key = b'%s:%s' % (username, password)
key = base64.b64encode(key)
auth = b'Basic %s' % key
headers['Authorization'] = auth
- Example for passing authentication details in Bearer Authentication.
auth = b'Bearer %s' % b'key'
headers['Authorization'] = auth
$ python3 -m doctest -v README.md