The Dataherald Python library provides convenient access to the Dataherald REST API from any Python 3.7+ application. The library includes type definitions for all request params and response fields, and offers both synchronous and asynchronous clients powered by httpx.
The API documentation can be found here.
pip install dataherald
The full API of this library can be found in api.md.
import os
from dataherald import Dataherald
client = Dataherald(
# This is the default and can be omitted
api_key=os.environ.get("DATAHERALD_API_KEY"),
# defaults to "production".
environment="staging",
)
db_connection_response = client.database_connections.create()
print(db_connection_response.id)
While you can provide an api_key
keyword argument,
we recommend using python-dotenv
to add DATAHERALD_API_KEY="My API Key"
to your .env
file
so that your API Key is not stored in source control.
Simply import AsyncDataherald
instead of Dataherald
and use await
with each API call:
import os
import asyncio
from dataherald import AsyncDataherald
client = AsyncDataherald(
# This is the default and can be omitted
api_key=os.environ.get("DATAHERALD_API_KEY"),
# defaults to "production".
environment="staging",
)
async def main() -> None:
db_connection_response = await client.database_connections.create()
print(db_connection_response.id)
asyncio.run(main())
Functionality between the synchronous and asynchronous clients is otherwise identical.
Nested request parameters are TypedDicts. Responses are Pydantic models, which provide helper methods for things like:
- Serializing back into JSON,
model.model_dump_json(indent=2, exclude_unset=True)
- Converting to a dictionary,
model.model_dump(exclude_unset=True)
Typed requests and responses provide autocomplete and documentation within your editor. If you would like to see type errors in VS Code to help catch bugs earlier, set python.analysis.typeCheckingMode
to basic
.
When the library is unable to connect to the API (for example, due to network connection problems or a timeout), a subclass of dataherald.APIConnectionError
is raised.
When the API returns a non-success status code (that is, 4xx or 5xx
response), a subclass of dataherald.APIStatusError
is raised, containing status_code
and response
properties.
All errors inherit from dataherald.APIError
.
import dataherald
from dataherald import Dataherald
client = Dataherald()
try:
client.database_connections.create()
except dataherald.APIConnectionError as e:
print("The server could not be reached")
print(e.__cause__) # an underlying Exception, likely raised within httpx.
except dataherald.RateLimitError as e:
print("A 429 status code was received; we should back off a bit.")
except dataherald.APIStatusError as e:
print("Another non-200-range status code was received")
print(e.status_code)
print(e.response)
Error codes are as followed:
Status Code | Error Type |
---|---|
400 | BadRequestError |
401 | AuthenticationError |
403 | PermissionDeniedError |
404 | NotFoundError |
422 | UnprocessableEntityError |
429 | RateLimitError |
>=500 | InternalServerError |
N/A | APIConnectionError |
Certain errors are automatically retried 2 times by default, with a short exponential backoff. Connection errors (for example, due to a network connectivity problem), 408 Request Timeout, 409 Conflict, 429 Rate Limit, and >=500 Internal errors are all retried by default.
You can use the max_retries
option to configure or disable retry settings:
from dataherald import Dataherald
# Configure the default for all requests:
client = Dataherald(
# default is 2
max_retries=0,
)
# Or, configure per-request:
client.with_options(max_retries=5).database_connections.create()
By default requests time out after 1 minute. You can configure this with a timeout
option,
which accepts a float or an httpx.Timeout
object:
from dataherald import Dataherald
# Configure the default for all requests:
client = Dataherald(
# 20 seconds (default is 1 minute)
timeout=20.0,
)
# More granular control:
client = Dataherald(
timeout=httpx.Timeout(60.0, read=5.0, write=10.0, connect=2.0),
)
# Override per-request:
client.with_options(timeout=5 * 1000).database_connections.create()
On timeout, an APITimeoutError
is thrown.
Note that requests that time out are retried twice by default.
We use the standard library logging
module.
You can enable logging by setting the environment variable DATAHERALD_LOG
to debug
.
$ export DATAHERALD_LOG=debug
In an API response, a field may be explicitly null
, or missing entirely; in either case, its value is None
in this library. You can differentiate the two cases with .model_fields_set
:
if response.my_field is None:
if 'my_field' not in response.model_fields_set:
print('Got json like {}, without a "my_field" key present at all.')
else:
print('Got json like {"my_field": null}.')
The "raw" Response object can be accessed by prefixing .with_raw_response.
to any HTTP method call.
from dataherald import Dataherald
client = Dataherald()
response = client.database_connections.with_raw_response.create()
print(response.headers.get('X-My-Header'))
database_connection = response.parse() # get the object that `database_connections.create()` would have returned
print(database_connection.id)
These methods return an APIResponse
object.
You can directly override the httpx client to customize it for your use case, including:
- Support for proxies
- Custom transports
- Additional advanced functionality
import httpx
from dataherald import Dataherald
client = Dataherald(
# Or use the `DATAHERALD_BASE_URL` env var
base_url="http://my.test.server.example.com:8083",
http_client=httpx.Client(
proxies="http://my.test.proxy.example.com",
transport=httpx.HTTPTransport(local_address="0.0.0.0"),
),
)
By default the library closes underlying HTTP connections whenever the client is garbage collected. You can manually close the client using the .close()
method if desired, or with a context manager that closes when exiting.
This package generally follows SemVer conventions, though certain backwards-incompatible changes may be released as minor versions:
- Changes that only affect static types, without breaking runtime behavior.
- Changes to library internals which are technically public but not intended or documented for external use. (Please open a GitHub issue to let us know if you are relying on such internals).
- Changes that we do not expect to impact the vast majority of users in practice.
We take backwards-compatibility seriously and work hard to ensure you can rely on a smooth upgrade experience.
We are keen for your feedback; please open an issue with questions, bugs, or suggestions.
Python 3.7 or higher.