I'm trying to create several URLs on my serv thanks to a loop . The issue is that each function I create in a app.route can't have the same name than the others . And I don't know how to create different function names ...
Here is the code :
json_tweets = []
for line in open('C:\Users\Benjamin\Desktop\DashboardProject\last_rated_set.json',"r"):
json_tweets.append(json.loads(line,"ISO-8859-1"))
cashtag_tab = []
for tweet in json_tweets:
if not(tweet['cashtag'] in cashtag_tab) :
cashtag_tab.append(tweet['cashtag'])
for i in range(0,(len(cashtag_tab)-1)) :
var=cashtag_tab[i]
#app.route("/"+var)
def company(var) :
finance=Share(var)
datas = finance.get_historical('2014-01-01', '2014-12-31')
datas = json.dumps(datas, default=json_util.default)
return datas
I'm getting the error AssertionError : View function mapping is overwritting an existing endpoint function : company
This fails because Flask derives the endpoint name from the function by default, but it would anyway fail later because the function company requires an argument var and the route is not parameterised. The simplest option would be just checking the value inside the handler:
#api.route('/<var>')
def company(var):
if var not in cashtag_tab:
abort(404)
If you want all the routes to be in the routing map for any reason, I once needed a similar thing and came up with something like this:
def url_family(source, methods=('GET',)):
def decorator(f):
for entry in source:
# create a handler that delegates to your function
def view_func(entry=entry, **kwargs):
return f(entry, **kwargs)
endpoint = '{0}_{1}'.format(f.__name__, entry)
url = '/{0}'.format(entry)
api.add_url_rule(url,
methods=methods,
endpoint=endpoint,
view_func=view_func)
return decorator
Then you register the handlers as:
#url_family(cashtag_tab)
def company(var):
...
Assuming that you are using flask now, you should consider Custom URL Converter. Check links below
http://flask.pocoo.org/docs/0.10/api/#flask.Flask.url_map - url_map UrlConverter API
https://exploreflask.com/views.html#url-converters - example url converter
https://stackoverflow.com/a/5872904/3451543 - RegexConverter by Philip Southam
Anyway, specifying more details on your question is always helpful to get accurate answer :)
Related
I have a GET method with requested parameter in path:
#router.get('/users/{user_id}')
async def get_user_from_string(user_id: str):
return User(user_id)
Is it possible to get base url raw path (i.e., '/users/{user_id}') from the request?
I have tried to use the following way:
path = [route for route in request.scope['router'].routes if
route.endpoint == request.scope['endpoint']][0].path
But it doesn't work and I get:
AttributeError: 'Mount' object has no attribute 'endpoint'
The below solution worked fine for me
using the string replace with count parameter replaces the first occurence only. And request.path_params will return the path parameters in the sequence you take it in the request.
def get_raw_path(request):
path = request.url.path
for key, val in request.path_params.items():
path = path.replace(val, F'{{{key}}}',1)
return path
As per FastAPI documentation:
As FastAPI is actually Starlette underneath, with a layer of several
tools on top, you can use Starlette's Request object directly when you
need to.
Thus, you can use Request object to get the URL path. For instance:
from fastapi import Request
#app.get('/users/{user_id}')
def get_user(user_id: str, request: Request):
return request.url.path
Output (if the received user_id was 1):
/users/1
Update
If, however, what you need is the original route path, i.e., /users/{user_id}, you could use the below. The way it works is by getting the root_path first—which would normally be an empty string, unless you have mounted sub-application(s) to the top-level app (e.g., app.mount("/subapi", subapi)), and hence, you need the result to be prefixed with that specific path /subapi—and then append to it the route's path , which you can get from the APIRoute object. Example:
from fastapi import Request
#app.get('/users/{user_id}')
def get_user(user_id: str, request: Request):
path = request.scope['root_path'] + request.scope['route'].path
return path
Output:
/users/{user_id}
I'm working on implementing this for OpenTelemetry and the way to get the original route with the data that's available is as follows:
def get_route_from_request(req):
root_path = req.scope.get("root_path", "")
route = scope.get("route")
if not route:
return None
path_format = getattr(route, "path_format", None)
if path_format:
return f"{route_path}{path_format}"
return None
Note that the accepted answer is not returning what was asked, as it returns the path as received by the server.
None of the other answers deal with mounted apps.
And finally, answers checking the name of the endpoint are also wrong as the same function could be used in different endpoints.
Having found both the answers to not work I'll share what I use.
It's not great as if there's shared values in path params it will not work
path = request.url.path
for key, val in request.path_params.items():
path = path.replace(val, F'{{{key}}}')
You can use the APIRout object property in the request to get the actual path
example:
raw_path = request.scope['route'].path
#'/user/{id}'
I'm not sure if I used the right terms in the title. This maybe a known way to program interface functions for a subsystem or module but because I don't know the keywords, I'm not finding the results in my search queries.
I want to create a function whose intention can be clearly described in the functions name but the parameters are flexible. I want to write the function to be generic enough so that the function can complete the intention with whatever parameters it receives from whichever caller.
Let's take a function do_foo.
do_foo can take in some_obj whose attributes allows do_foo to do its work. Additionally, do_foo can just take in the individual attributes it cares about like obj_attr0 or obj_attr1 and perform the same work. In both cases, the expected result is the same as well.
So this would look something like this:
Class SomeObj():
def __init__(self, obj_attr0, obj_attr1, obj_attrN):
self.obj_attr0 = None
self.obj_attr1 = None
self.obj_attrN = None # denotes an N number of attributes
def do_foo(params)
# unpack params. do_foo requires obj_attr0 and obj_attr1 and so its searching it in the params iterable
# determine which data is passed in
# execute the work the same way regardless of what form the data is passed in
pass
obj_attr0 = None
obj_attr1 = None
obj_attrN = None
some_obj = SomeObj(obj_attr0, obj_attr1, obj_attrN)
# One can either call with a subset of attributes that would make up SomeObj or SomeObj itself if all the information is there. E.g.:
params = (some_obj)
do_foo(params)
# OR
params = (obj_att0, obj_attr1)
do_foo(params)
I know python offers *args and **kwargs facilities that offer the flexibility above. I'm looking for some examples of where the implementation lends itself to reducing pitfalls. What is a good way to implement the above? And if there are any resources out there what are examples/articles/or terms that describe the above style of programming? Clearly, I'm trying to write my interface functions to be generic and usable in multiple logic paths where the users has its data in different forms where sticking to a specific parameter list is limiting.
Short answer:
You can use function decorators to do this
Long answer:
I have a concrete example for you. It might not be the prettiest code but it does something similar to what you are asking for.
Mini HTTP Testing library
I made a mini HTTP testing library because I make my REST http tests in python, and I realized that I always write the same code again and again. So I made a more general setup
The core
The core is kind of ugly and this is the part I don't want to write again and again.
Just skip this part quick and check how it is used in the interface section.
Then if you like it you can go back and try to understand how it is all tied together.
# base.py
import json, requests, inspect
# This function drops invallid parameters
def request(*args, **kwargs):
allowed = inspect.signature(requests.Session.request).parameters
return {k:v for (k,v) in kwargs.items() if k in allowed}
def response(r, code):
if r.status_code != code:
print(r.text)
return
data = r.json()
if data:
print(json.dumps(data, indent=2, ensure_ascii=False))
return data
# This is the core function it is not pretty but it creates all the abstaction in multiple levels of decorations.
def HTTP(base_url):
def outer(func_one):
def over(*args_one, **kwargs_one):
req, url, code = func_one(*args_one, **kwargs_one)
url = base_url + url
def inner(func_two):
def under(*args_two, **kwargs_two):
allowed = inspect.signature(func_two).parameters
kwparams = {k:v for (k,v) in kwargs_two.items() if k in allowed}
from_inner = func_two(*args_two, **kwparams)
u = url.format(id=kwargs_two.pop('_id')) if '{id}' in url else url
r = req(u, **request(**kwargs_two, **from_inner))
return response(r, code)
return under
return inner
return over
return outer
The interface
The interface functions are all each decorated by the HTTP function which makes them a HTTP caller function, it is still abstract since it will return a function.
Note: interface is just what I call it but it is really just functions which returns functions based on the HTTP decorator
BASE_URL = "https://example.com"
#HTTP(BASE_URL)
def POST(url, code=200): return requests.post, url, code
#HTTP(BASE_URL)
def PUT(url, code=200): return requests.put, url, code
#HTTP(BASE_URL)
def DELETE(url, code=200): return requests.delete, url, code
#HTTP(BASE_URL)
def GET(url, code=200): return requests.get, url, code
A middleware function
When one of the interface functions are decorated with this one then they need a token.
def AUTH(func):
def inner(token, *args, **kwargs):
headers = {'Authorization': f'bearer {token}'}
return func(*args, **kwargs, headers=headers)
return inner
The implementation
The interface can be used for many implementations.
Here I use the interface of POST, PUT, GET and DELETE for the user model.
This is the final decoration, and the functions returned will actually return content instead of other functions.
# users.py
from httplib.base import (
POST,
GET,
DELETE,
PUT,
AUTH,
request
)
#POST('/users',200)
def insert(user):
return request(json=user)
#AUTH
#GET('/users')
def find(_filter={}):
return request(params=_filter)
#AUTH
#GET('/users/{id}')
def find_one(_id):
return request()
#AUTH
#DELETE('/users/{id}')
def delete(_id):
return request()
#AUTH
#PUT('/users/{id}')
def update(_id, updates={}):
return request(json=updates)
Operation
Here you can see how the users delete insert and find functions work.
from httplib import users
def create_and_delete_users(token, n): return [
users.delete(token, _id=x['user']['id'])
for x in [
users.insert(user={
'username' : f'useruser{str(i).zfill(2)}',
'password' : 'secretpassword',
'email' : f'useruser{str(i).zfill(2)}#mail.com',
'gender' : 'male',
}) for i in range(n)]
]
def find_all_and_then_find_each(token): return [
users.find_one(token, _id=x['id'])
for x in users.find(token)['data']
]
I hope this was helpful.
I am trying to get Flask converters up and running as shown in the manual: http://flask.pocoo.org/docs/0.12/api/#url-route-registrations
Right now, I have currently four pages defined like so:
#app.route('/page1')
def page1():
return render_template("page1.html")
#app.route('/page2')
def page2():
return render_template("page2.html")
#app.route('/page3')
def page3():
return render_template("page3.html")
#app.route('/page4')
def page4():
return render_template("page4.html")
I could not find yet a way to automate this repetitive notation and would be grateful for hints.
You can create dynamic routes by using converters.
You'd then define your route like this:
#app.route("/<page>")
def pages(page):
return render_template(page + ".html")
Which will accept all of your paths.
You can also be more specific in what you allow in the dynamic paths, such as:
#app.route("/post/<int:post_id>")
def show_post(post_id):
pass
Which would accept /post/1, /post/2, /post/100 but not /post/test.
In Flask, when I have several routes for the same function,
how can I know which route is used at the moment?
For example:
#app.route("/antitop/")
#app.route("/top/")
#requires_auth
def show_top():
....
How can I know, that now route was called using /top/ or /antitop/?
UPDATE
I know about request.path I don't want use it, because the request can be rather complex, and I want repeat the routing logic in the function. I think that the solution with url_rule it the best one.
Simply use request.path.
from flask import request
...
#app.route("/antitop/")
#app.route("/top/")
#requires_auth
def show_top():
... request.path ...
the most 'flasky' way to check which route triggered your view is, by request.url_rule.
from flask import request
rule = request.url_rule
if 'antitop' in rule.rule:
# request by '/antitop'
elif 'top' in rule.rule:
# request by '/top'
Another option is to use endpoint variable:
#app.route("/api/v1/generate_data", methods=['POST'], endpoint='v1')
#app.route("/api/v2/generate_data", methods=['POST'], endpoint='v2')
def generate_data():
version = request.endpoint
return version
If you want different behaviour to each route, the right thing to do is create two function handlers.
#app.route("/antitop/")
#requires_auth
def top():
...
#app.route("/top/")
#requires_auth
def anti_top():
...
In some cases, your structure makes sense. You can set values per route.
#app.route("/antitop/", defaults={'_route': 'antitop'})
#app.route("/top/", defaults={'_route': 'top'})
#requires_auth
def show_top(_route):
# use _route here
...
It seems to me that if you have a situation where it matters, you shouldn't be using the same function in the first place. Split it out into two separate handlers, which each call a common fiction for the shared code.
One thing I have to add to the answers above is that
request.path preserves the url parameter value(s) passed while request.url_rule gives you the url_rule you defined without the passed parameter(s)
#app.route("/antitop/")
#app.route("/top/")
#requires_auth
def show_top():
request.path
request.url_rule
# -> both will give you "/antitop/" or "/top/"
....
#app.route("/antitop/<username>")
#app.route("/top/<username>")
#requires_auth
def show_top():
request.path
# -> gives you "/antitop/name" or ...
request.url_rule
# -> gives you "/antitop/<username>" or ...
....
Since you don't have any variable routes definey (yet!) you don't have to care but for the sake of saving you work and the headache in the future I'd still suggest using request.path.
In flask, I can do this:
render_template("foo.html", messages={'main':'hello'})
And if foo.html contains {{ messages['main'] }}, the page will show hello. But what if there's a route that leads to foo:
#app.route("/foo")
def do_foo():
# do some logic here
return render_template("foo.html")
In this case, the only way to get to foo.html, if I want that logic to happen anyway, is through a redirect:
#app.route("/baz")
def do_baz():
if some_condition:
return render_template("baz.html")
else:
return redirect("/foo", messages={"main":"Condition failed on page baz"})
# above produces TypeError: redirect() got an unexpected keyword argument 'messages'
So, how can I get that messages variable to be passed to the foo route, so that I don't have to just rewrite the same logic code that that route computes before loading it up?
You could pass the messages as explicit URL parameter (appropriately encoded), or store the messages into session (cookie) variable before redirecting and then get the variable before rendering the template. For example:
from flask import session, url_for
def do_baz():
messages = json.dumps({"main":"Condition failed on page baz"})
session['messages'] = messages
return redirect(url_for('.do_foo', messages=messages))
#app.route('/foo')
def do_foo():
messages = request.args['messages'] # counterpart for url_for()
messages = session['messages'] # counterpart for session
return render_template("foo.html", messages=json.loads(messages))
(encoding the session variable might not be necessary, flask may be handling it for you, but can't recall the details)
Or you could probably just use Flask Message Flashing if you just need to show simple messages.
I found that none of the answers here applied to my specific use case, so I thought I would share my solution.
I was looking to redirect an unauthentciated user to public version of an app page with any possible URL params. Example:
/app/4903294/my-great-car?email=coolguy%40gmail.com to
/public/4903294/my-great-car?email=coolguy%40gmail.com
Here's the solution that worked for me.
return redirect(url_for('app.vehicle', vid=vid, year_make_model=year_make_model, **request.args))
Hope this helps someone!
I'm a little confused. "foo.html" is just the name of your template. There's no inherent relationship between the route name "foo" and the template name "foo.html".
To achieve the goal of not rewriting logic code for two different routes, I would just define a function and call that for both routes. I wouldn't use redirect because that actually redirects the client/browser which requires them to load two pages instead of one just to save you some coding time - which seems mean :-P
So maybe:
def super_cool_logic():
# execute common code here
#app.route("/foo")
def do_foo():
# do some logic here
super_cool_logic()
return render_template("foo.html")
#app.route("/baz")
def do_baz():
if some_condition:
return render_template("baz.html")
else:
super_cool_logic()
return render_template("foo.html", messages={"main":"Condition failed on page baz"})
I feel like I'm missing something though and there's a better way to achieve what you're trying to do (I'm not really sure what you're trying to do)
You can however maintain your code and simply pass the variables in it separated by a comma: if you're passing arguments, you should rather use render_template:
#app.route("/baz")
def do_baz():
if some_condition:
return render_template("baz.html")
else:
return render_template("/foo", messages={"main":"Condition failed on page baz"})