Python type hinting on imported modules









up vote
3
down vote

favorite
2












I find that the autocomplete for Flask is somewhat lacking--this is because internally, context-specific objects such as current_app, request, and logger are actually LocalProxys. Thus PyCharm reasonably has no idea what to do with this type.



So the obvious solution to this, to me would be to apply type hints on the imported modules. Except you can't do that! As of Python 3.7 there appears to be no such syntax to facilitate this.



So the next-obvious solution would be to make local copies of each context-specific module with the type explicitly set like so:



from logging import Logger
from flask import Flask, Request, Blueprint, request, current_app as app

app: Flask = app
logger: Logger = app.logger
request: Request = request


...which works until you actually attempt to start the server, in which case the application crashes because of a RuntimeError: Working outside of application context.



It turns out that we can actually encapsulate the relevant type hints inside of a class or other scope inside of the application context.



@foo_blueprint.route('/foo', methods=['GET'])
def foo(cls):
_app: Flask = app
_logger: Logger = app.logger
_request: Request = request
# ...


...which works but is incredibly awkward in every imaginable sense.



Is there a reasonable solution for getting proper type hints inside of an application context in Flask?










share|improve this question





















  • maybe it will be useful
    – Danila Ganchar
    Nov 9 at 8:42










  • Flask is only supported in the professional edition of Pycharm jetbrains.com/help/pycharm/flask.html Which version of Pycharm are you using: Community Edition or Professional?
    – Eskapp
    Nov 9 at 16:01










  • I use the Community Edition (was not aware of dedicated support of particular libraries), but this question was written in general for those awful libraries that smash together types at runtime (such as Boto3).
    – I'll Eat My Hat
    Nov 10 at 18:13










  • cont'd: Flask as an example was merely the latest, most widely used, and has what is probably the simplest problems and workarounds.
    – I'll Eat My Hat
    Nov 10 at 18:21














up vote
3
down vote

favorite
2












I find that the autocomplete for Flask is somewhat lacking--this is because internally, context-specific objects such as current_app, request, and logger are actually LocalProxys. Thus PyCharm reasonably has no idea what to do with this type.



So the obvious solution to this, to me would be to apply type hints on the imported modules. Except you can't do that! As of Python 3.7 there appears to be no such syntax to facilitate this.



So the next-obvious solution would be to make local copies of each context-specific module with the type explicitly set like so:



from logging import Logger
from flask import Flask, Request, Blueprint, request, current_app as app

app: Flask = app
logger: Logger = app.logger
request: Request = request


...which works until you actually attempt to start the server, in which case the application crashes because of a RuntimeError: Working outside of application context.



It turns out that we can actually encapsulate the relevant type hints inside of a class or other scope inside of the application context.



@foo_blueprint.route('/foo', methods=['GET'])
def foo(cls):
_app: Flask = app
_logger: Logger = app.logger
_request: Request = request
# ...


...which works but is incredibly awkward in every imaginable sense.



Is there a reasonable solution for getting proper type hints inside of an application context in Flask?










share|improve this question





















  • maybe it will be useful
    – Danila Ganchar
    Nov 9 at 8:42










  • Flask is only supported in the professional edition of Pycharm jetbrains.com/help/pycharm/flask.html Which version of Pycharm are you using: Community Edition or Professional?
    – Eskapp
    Nov 9 at 16:01










  • I use the Community Edition (was not aware of dedicated support of particular libraries), but this question was written in general for those awful libraries that smash together types at runtime (such as Boto3).
    – I'll Eat My Hat
    Nov 10 at 18:13










  • cont'd: Flask as an example was merely the latest, most widely used, and has what is probably the simplest problems and workarounds.
    – I'll Eat My Hat
    Nov 10 at 18:21












up vote
3
down vote

favorite
2









up vote
3
down vote

favorite
2






2





I find that the autocomplete for Flask is somewhat lacking--this is because internally, context-specific objects such as current_app, request, and logger are actually LocalProxys. Thus PyCharm reasonably has no idea what to do with this type.



So the obvious solution to this, to me would be to apply type hints on the imported modules. Except you can't do that! As of Python 3.7 there appears to be no such syntax to facilitate this.



So the next-obvious solution would be to make local copies of each context-specific module with the type explicitly set like so:



from logging import Logger
from flask import Flask, Request, Blueprint, request, current_app as app

app: Flask = app
logger: Logger = app.logger
request: Request = request


...which works until you actually attempt to start the server, in which case the application crashes because of a RuntimeError: Working outside of application context.



It turns out that we can actually encapsulate the relevant type hints inside of a class or other scope inside of the application context.



@foo_blueprint.route('/foo', methods=['GET'])
def foo(cls):
_app: Flask = app
_logger: Logger = app.logger
_request: Request = request
# ...


...which works but is incredibly awkward in every imaginable sense.



Is there a reasonable solution for getting proper type hints inside of an application context in Flask?










share|improve this question













I find that the autocomplete for Flask is somewhat lacking--this is because internally, context-specific objects such as current_app, request, and logger are actually LocalProxys. Thus PyCharm reasonably has no idea what to do with this type.



So the obvious solution to this, to me would be to apply type hints on the imported modules. Except you can't do that! As of Python 3.7 there appears to be no such syntax to facilitate this.



So the next-obvious solution would be to make local copies of each context-specific module with the type explicitly set like so:



from logging import Logger
from flask import Flask, Request, Blueprint, request, current_app as app

app: Flask = app
logger: Logger = app.logger
request: Request = request


...which works until you actually attempt to start the server, in which case the application crashes because of a RuntimeError: Working outside of application context.



It turns out that we can actually encapsulate the relevant type hints inside of a class or other scope inside of the application context.



@foo_blueprint.route('/foo', methods=['GET'])
def foo(cls):
_app: Flask = app
_logger: Logger = app.logger
_request: Request = request
# ...


...which works but is incredibly awkward in every imaginable sense.



Is there a reasonable solution for getting proper type hints inside of an application context in Flask?







python flask pycharm type-hinting python-3.7






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 9 at 8:10









I'll Eat My Hat

1388




1388











  • maybe it will be useful
    – Danila Ganchar
    Nov 9 at 8:42










  • Flask is only supported in the professional edition of Pycharm jetbrains.com/help/pycharm/flask.html Which version of Pycharm are you using: Community Edition or Professional?
    – Eskapp
    Nov 9 at 16:01










  • I use the Community Edition (was not aware of dedicated support of particular libraries), but this question was written in general for those awful libraries that smash together types at runtime (such as Boto3).
    – I'll Eat My Hat
    Nov 10 at 18:13










  • cont'd: Flask as an example was merely the latest, most widely used, and has what is probably the simplest problems and workarounds.
    – I'll Eat My Hat
    Nov 10 at 18:21
















  • maybe it will be useful
    – Danila Ganchar
    Nov 9 at 8:42










  • Flask is only supported in the professional edition of Pycharm jetbrains.com/help/pycharm/flask.html Which version of Pycharm are you using: Community Edition or Professional?
    – Eskapp
    Nov 9 at 16:01










  • I use the Community Edition (was not aware of dedicated support of particular libraries), but this question was written in general for those awful libraries that smash together types at runtime (such as Boto3).
    – I'll Eat My Hat
    Nov 10 at 18:13










  • cont'd: Flask as an example was merely the latest, most widely used, and has what is probably the simplest problems and workarounds.
    – I'll Eat My Hat
    Nov 10 at 18:21















maybe it will be useful
– Danila Ganchar
Nov 9 at 8:42




maybe it will be useful
– Danila Ganchar
Nov 9 at 8:42












Flask is only supported in the professional edition of Pycharm jetbrains.com/help/pycharm/flask.html Which version of Pycharm are you using: Community Edition or Professional?
– Eskapp
Nov 9 at 16:01




Flask is only supported in the professional edition of Pycharm jetbrains.com/help/pycharm/flask.html Which version of Pycharm are you using: Community Edition or Professional?
– Eskapp
Nov 9 at 16:01












I use the Community Edition (was not aware of dedicated support of particular libraries), but this question was written in general for those awful libraries that smash together types at runtime (such as Boto3).
– I'll Eat My Hat
Nov 10 at 18:13




I use the Community Edition (was not aware of dedicated support of particular libraries), but this question was written in general for those awful libraries that smash together types at runtime (such as Boto3).
– I'll Eat My Hat
Nov 10 at 18:13












cont'd: Flask as an example was merely the latest, most widely used, and has what is probably the simplest problems and workarounds.
– I'll Eat My Hat
Nov 10 at 18:21




cont'd: Flask as an example was merely the latest, most widely used, and has what is probably the simplest problems and workarounds.
– I'll Eat My Hat
Nov 10 at 18:21

















active

oldest

votes











Your Answer






StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);













draft saved

draft discarded


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53221949%2fpython-type-hinting-on-imported-modules%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes















draft saved

draft discarded
















































Thanks for contributing an answer to Stack Overflow!


  • Please be sure to answer the question. Provide details and share your research!

But avoid


  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • Please be sure to answer the question. Provide details and share your research!

But avoid


  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53221949%2fpython-type-hinting-on-imported-modules%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

𛂒𛀶,𛀽𛀑𛂀𛃧𛂓𛀙𛃆𛃑𛃷𛂟𛁡𛀢𛀟𛁤𛂽𛁕𛁪𛂟𛂯,𛁞𛂧𛀴𛁄𛁠𛁼𛂿𛀤 𛂘,𛁺𛂾𛃭𛃭𛃵𛀺,𛂣𛃍𛂖𛃶 𛀸𛃀𛂖𛁶𛁏𛁚 𛂢𛂞 𛁰𛂆𛀔,𛁸𛀽𛁓𛃋𛂇𛃧𛀧𛃣𛂐𛃇,𛂂𛃻𛃲𛁬𛃞𛀧𛃃𛀅 𛂭𛁠𛁡𛃇𛀷𛃓𛁥,𛁙𛁘𛁞𛃸𛁸𛃣𛁜,𛂛,𛃿,𛁯𛂘𛂌𛃛𛁱𛃌𛂈𛂇 𛁊𛃲,𛀕𛃴𛀜 𛀶𛂆𛀶𛃟𛂉𛀣,𛂐𛁞𛁾 𛁷𛂑𛁳𛂯𛀬𛃅,𛃶𛁼

Edmonton

Crossroads (UK TV series)