Tips, Tricks, & Extras¶
Here are a few ways to simplify consumer definitions.
Decorating All Request Methods in a Class¶
To apply a decorator of this library across all methods of a
uplink.Consumer
subclass, you can simply decorate the class
rather than each method individually:
@uplink.timeout(60)
class GitHub(uplink.Consumer):
@uplink.get("/repositories")
def get_repos(self):
"""Dump every public repository."""
@uplink.get("/organizations")
def get_organizations(self):
"""List all organizations."""
Hence, the consumer defined above is equivalent to the following, slightly more verbose definition:
class GitHub(uplink.Consumer):
@uplink.timeout(60)
@uplink.get("/repositories")
def get_repos(self):
"""Dump every public repository."""
@uplink.timeout(60)
@uplink.get("/organizations")
def get_organizations(self):
"""List all organizations."""
Adopting the Argument’s Name¶
Several function argument annotations accept a name
parameter
on construction. For instance, the Path
annotation
uses the name
parameter to associate the function argument to
a URI path parameter:
class GitHub(uplink.Consumer):
@uplink.get("users/{username}")
def get_user(self, username: uplink.Path("username")): pass
For such annotations, you can omit the name
parameter to have the
annotation adopt the name of its corresponding method argument.
For instance, from the previous example, we can omit naming the
Path
annotation since the corresponding argument’s
name, username
, matches the intended URI path parameter.
class GitHub(uplink.Consumer):
@uplink.get("users/{username}")
def get_user(self, username: uplink.Path): pass
Some annotations that support this behavior include:
Path
, uplink.Field
, Part
Header
, and uplink.Query
.
Annotating Your Arguments For Python 2.7¶
There are several ways to annotate arguments. Most examples in this
documentation use function annotations, but this approach is unavailable
for Python 2.7 users. Instead, you should either utilize the method
annotation args
or use the optional args
parameter of the HTTP method decorators (e.g., uplink.get
).
Using uplink.args
¶
One approach for Python 2.7 users involves using the method annotation
args
, arranging annotations in the same order as
their corresponding function arguments (again, ignore self
):
class GitHub(uplink.Consumer):
@uplink.args(uplink.Url, uplink.Path)
@uplink.get
def get_commit(self, commits_url, sha): pass
The args
argument¶
New in version v0.5.0.
The HTTP method decorators (e.g., uplink.get
) support an
optional positional argument args
, which accepts a
list of annotations, arranged in the same order as their corresponding
function arguments,
class GitHub(uplink.Consumer):
@uplink.get(args=(uplink.Url, uplink.Path))
def get_commit(self, commits_url, sha): pass
or a mapping of argument names to annotations:
class GitHub(uplink.Consumer):
@uplink.get(args={"commits_url": uplink.Url, "sha": uplink.Path})
def get_commit(self, commits_url, sha): pass
Annotating __init__()
Arguments¶
Function annotations like Query
and Header
can
be used with constructor arguments of a Consumer
subclass.
When a new consumer instance is created, the value of these arguments are
applied to all requests made through that instance.
For example, the following consumer accepts the API access token as the
constructor argument access_token
:
class GitHub(uplink.Consumer):
def __init__(self, access_token: uplink.Query):
...
@uplink.post("/user")
def update_user(self, **info: Body):
"""Update the authenticated user"""
Now, all requests made from an instance of this consumer class will be authenticated with the access token passed in at initialization:
github = GitHub("my-github-access-token")
# This request will include the `access_token` query parameter set from
# the constructor argument.
github.update_user(bio="Beam me up, Scotty!")
The Consumer’s _inject()
Method¶
As an alternative to Annotating __init__() Arguments and
Persistence Across Requests from a Consumer, you can achieve a similar behavior with more control by
using the Consumer._inject()
method. With this method, you can
calculate request properties within plain old python methods.
class TodoApp(uplink.Consumer):
def __init__(self, base_url, username, password):
super(TodoApp, self).__init__(base_url=base_url)
# Create an access token
api_key = create_api_key(username, password)
# Inject it.
self._inject(uplink.Query("api_key").with_value(api_key))
Similar to the annotation style, request properties added with
_inject()
method are applied to all requests made
through the consumer instance.
Extend Consumer Methods to Reduce Boilerplate¶
New in version v0.9.0.
Consumer methods are methods decorated with Uplink’s HTTP method decorators,
such as @get
or @post
(see
here for more background).
Consumer methods can be used as decorators to minimize duplication across similar consumer method definitions.
For example, you can define consumer method templates like so:
from uplink import Consumer, get, json, returns
@returns.json
@json
@get
def get_json():
"""Template for GET request that consumes and produces JSON."""
class GitHub(Consumer):
@get_json("/users/{user}")
def get_user(self, user):
"""Fetches a specific GitHub user."""
Further, you can use this technique to remove duplication across definitions of similar consumer methods, whether or not the methods are defined in the same class:
from uplink import Consumer, get, params, timeout
class GitHub(Consumer):
@timeout(10)
@get("/users/{user}/repos")
def get_user_repos(self, user):
"""Retrieves the repos that the user owns."""
# Extends the above method to define a variant:
@params(type="member")
@get_user_repos
def get_repos_for_collaborator(self, user):
"""
Retrieves the repos for which the given user is
a collaborator.
"""
class EnhancedGitHub(Github):
# Updates the return type of an inherited method.
@GitHub.get_user_repos
def get_user_repos(self, user) -> List[Repo]:
"""Retrieves the repos that the user owns."""