Python circular import typing. py, your class A: has not executed, and does not exist.

Python circular import typing v1 = v1 self. $ circular_import_examples % python3 . 7 in mind. py depend on each other: /package __init__. May 20, 2022 · How do I fix this circular import error? I check if a field's type is str in __post_init__ then only eval it to avoid evaling a type if future versions of Python Jul 8, 2022 · In python, a module can be made by importing other modules. TYPE_CHECKING: import expensive_mod def a_func(arg: 'expensive_mod. This constant is False at runtime, but True when mypy (and other type-checking tools) evaluate your code. This can be solved using from __future__ import annotations (tested with Python 3. Edge import Edge # ^^^^ # TCH004: Import is used for more than type hinting. Two python modules. Sep 12, 2023 · PS: Circular relative imports can work, as long as you’re importing modules, not their contents (e. When two or more models import one another in Python, the importing connection is repeated, turning the call into an infinite circle. In order to do the action, the Actor needs to get_data() from the Director. 11以降からはデフォルトの挙動となるので不要）、且つ3. This is strictly a cycle induced by type hinting for static analysis. 💡 Example: Imagine you have two Python files: vehicles. py to use the filter functions, but SelectionLib. Here’s an example of a Python ImportError: cannot import name thrown due to a circular dependency. This tool automatically analyzes the Dec 11, 2023 · For types like strings, Python assumes that anything with single or double quotes around it will be a string. py and test2. Sep 24, 2022 · The imported class is unavailable in the Python library. Circular imports are always annoying when they arise in Python, and type hints make them more common. a import A, but in a. from __future__ import annotations from typing import TYPE_CHECKING if TYPE_CHECKING: from . Rewrite and/or rearrange your modules so that circular imports aren't need Dec 17, 2019 · The former is done only once, while the latter at each import statement. Line 3: We have imported typing. So, again, no imports, no import cycles; however, if you had two or maybe even more modules in the first place, you probably had them for a reason. You can use this to not have the import actually happen when you run the code, but still remain in the script for the sake of type hinting. These two modules depend on each other. I bump into this issue from time to time. Circular imports which are required to use static typing annotations are not a design problem; from __future__ import annotations & if typing. Also SOLID says depend on abstractions not concretions, so if you do the import then the highest quality practice is to depend on an abc. ImportError: Cannot import name X is a python exception that is related to the circular imports, but the exception tells nothing about where or what. #a/interface. Circular imports are not the ultimate evil to be avoided at all This is a fundamental problem with circular dependencies. (Some parts may still be specific to mypy. May 12, 2022 · Use the TYPE_CHECKING flag from typing and make the class a string. py, your class A: has not executed, and does not exist. I am aware of the following import options (which work Oct 29, 2024 · There is a common circular reference problem in python’s static typing. TYPE_CHECKING: from first import A class B: def process_a(a: "A"): This will permit the two files to import each other at runtime, but let type checkers perform work correctly Jan 24, 2022 · 2のfrom typing import TYPE_CHECKING はサードパーティーの静的型検査器（mypyなど）がTrueと仮定する特別な定数です。ライブラリ自体を実行するとFalseになります。 3のif TYPE_CHECKING: は2で出てきた定数を使用して、importするかどうかを判断します。これにより、PyCharm Apr 6, 2016 · I have a circular import because I reference a class in a type hint. import_module() et la gestion de l'attribut __all__ dans vos modules. The terms type expression and annotation expression denote specific subsets of Python expressions that are used in the type system. TYPE_CHECKING should be enough to resolve circular import issues related to use in annotations. class Node: def __init__(self): # This usage counts as "type hinting" (with the required import). Nonetheless, I assumed that once the question has been asked, there is a "requirement" to ensure the type. At runtime TYPE_CHECKING is False so the import will not execute, but a type checker should find this acceptable. Example: AClass. But we digress. . Jan 11, 2025 · As part of my recent efforts to reduce import times across modules, and reduce the need to directly import typing, a few things in typing stand out, especially where it interacts with static type checkers currently. TYPE_CHECKING: from second import B class A: def process_b(b: "B"): second. python import circular dependency (and perhaps Jun 21, 2023 · 循環インポートが一般的にどのように発生するか、およびそれらを修正する主な方法を学びます。 また、Python の型ヒントによって引き起こされる循環インポート エラーを修正する方法も学びます。 Aug 15, 2020 · Just place all your schema imports to the bottom of the file, after all classes, and call update_forward_refs(). py from __future__ import annotations from . py from utils import do_things class Example: pass def main(): ex = Example() do_things(ex) utils. 7～3. Mar 31, 2023 · using TYPE_CHECKING blocks for top level imports used for typing only is not "magic", it is standard, ubiquitous best practice when using typing. b import B, it goes to b. py file? __init__ file is responsible for importing and initializing packages. In some cases, a Circular dependency is created. Python typing이 무엇인지 모르시는 분들은 이 글을 읽어보시는 걸 추천합니다. x). All type expressions are also annotation expressions, but not all annotation expressions are type expressions. This can happen if each module tries to import the other before fully loading, leading to unpredictable behavior and runtime errors. 1 Oct 29, 2024 · With PEP 649 impending, I have some concerns that the tension between static-only and runtime type annotations may get worse. Nov 3, 2022 · Question: How is the circular import occurring? Can you show the minimal reproducible example that includes the other side of the circular import? Frequently the solution is to use normal import modulename imports instead of from modulename import name imports (the former delays resolving the contained names until time of use, which allows the circular import to work if the names from it aren Aug 16, 2023 · Ein zirkulärer Import in Python ist eine Situation, in der zwei oder mehr Python-Module voneinander abhängig sind und einen Schleifen- oder "Kreis"-Effekt im Abhängigkeitsgraphen erzeugen. Below, are the three approaches to solve Importerror: Cannot Import Name in Python: Circular Import ; Incorrect Module Reference; Typo in Import Statement ; Circular Import . a: A = a しかし、実は上 2 つのファイルは動作しません。 b. Specifically: there is tooling that automatically moves typing-only imports behind an if TYPE_CHECKING guard, which uses from __future__ import annotations as a “trigger”; this determining of intent will no longer be possible as a library author, I am torn between Jan 16, 2016 · 遇到的问题是因为模块之间存在循环导入（circular import），导致了。循环导入是指两个或多个模块相互导入对方，如模块A导入了模块B的方法，模块B又导入了模块A的方法，从而导致其中一个模块在完全初始化之前就被另一个模块尝试导入，进而引发错误。 Apr 14, 2024 · Circular imports in Python can be a developer’s nightmare, causing mysterious bugs and headaches. Circular relative imports can work, as long as you're importing modules, not their contents (e. Specifically: there is tooling that automatically moves typing-only imports behind an if TYPE_CHECKING guard, which uses from __future__ import annotations as a “trigger”; this determining of intent will no longer be possible as a library author, I am torn between Apr 8, 2024 · In Python, this happens when Module A needs something from Module B, but Module B also needs something from Module A. In fact, I'm having a hard time imagining any case where import * is warranted and circular dependencies are even a possibility. modules, which is the case during circular imports. My current solution forces me to import the child before importing the parent, and then adding some # noqa on the unused import. When a type hint contains names that have not been defined yet, that definition may be expressed as a string literal, to be resolved later. This is "not a problem" in Python where duck typing is just "the way". Just put one of the imports that would cause a cycle in a if TYPE_CHECKING-block. py in my packages with the abstract base class. Then change your type hint from ClassA to ”ClassA”. Example: import typing if typing. py and b. Switching to runtime, however, if I want to reflect on types Jan 16, 2021 · from typing import TYPE_CHECKING if TYPE_CHECKING: from a import A class B: def __init__ (self, a: A): self. py from example import Example from foo_bar import i_look_at_annotations @i_look_at_annotations def do_things(ex: Example): print(f"{ex} is an Example object") This code won’t run due to the circular Mar 28, 2024 · 这篇文章会以flask里遇到的一个问题为原型，介绍一下 cicular import产生的原因，以及python中使用import文件时，到底python在做什么。 1. ClassA import ClassA. There's some more subtlety when a package's __init__. expression Forward references are often useful when a class' type hints need to reference itself, or when you need to avoid a circular import through if typing. Dies kann zu Problemen in Ihrem Code führen, da das Importsystem von Python bei zirkulären Abhängigkeiten verwirrt werden kann. Here Feb 8, 2017 · Consider the following example python package where a. py Types of circular import problems. import typing if typing. TYPE_CHECKING constant as Jul 30, 2021 · ImportError: cannot import name 'BookManager' from partially initialized module 'mymodule. TYPE_CHECKING. To resolve circular imports, reorganize your code to eliminate the circular dependency. In the face of type checking cyclic import dependencies the recommendation here is to use typing. 빙글빙글. It’s a standoff, and nobody wins. Conditionally importing using TYPE_CHECK. For numbers, Python picks a number type. If you're doing from A import foo, there are ways around that (e. Illustration by the author. But sometimes there is an inherent circular dependency and the only way out are ugly hacks. Granted, that this scenario is far less likely when using from __future__ import annotations. Circular import dependencies typically fall into two categories depending on what you're trying to import and where you're using it inside each module. sibling_module import SomeClass). Since this is a circular import issue, I have used from __future__ import annotations in the top of . Aug 16, 2023 · Pythonで循環インポートを回避する別のテクニックは、importlib. Feb 27, 2020 · This article is written with Python 3. v2 = v2 Notice the absence of the quotes around the type hints. A says, "I need B to do my job," and at the same time, B says, "I need A to do my job. Circular imports and type hinting. orm import relationship class Foo(Base): __tablename__ = 'foo Apr 10, 2018 · Is there an actual circular dependency between modules? It seems like you don't need the response. Conclusion Circular dependency or import in Python is a code smell which is an indication of serious re-structuring and refactoring of the code. py b. The circular dependency between the classes is also not obvious. Now, circular imports usually involve just two modules, but it is possible for them to involve more. py) and they are dependent on each other, so declaring the import statements at the beginning would cause a circular import when executing the program. TYPE_CHECKING so that checkers are still able to import the “other” module to access its types. 6などの場合にはfutureのものも使えない Apr 13, 2024 · The type hints allow the functions to reference each other without causing import errors. If you’re using an older version, keep in mind that some things discussed in this article might work differently, especially if you’re using Python2. b = b class B: a: A Sep 27, 2019 · Sometimes a cleaner design or better decoupling might indeed get you out of the circular import hole. Jul 30, 2021 · ImportError: cannot import name 'BookManager' from partially initialized module 'mymodule. Sep 28, 2016 · For people struggling with cyclic imports when importing class only for Type checking: you will likely want to use a Forward Reference (PEP 484 - Type Hints):. Right know my hackish solution is to run the two files with run -i from IPython so it is like having a big single file and I avoid the circular import. 19 hours ago · The Python typing system is standardised via PEPs, so this reference should broadly apply to most Python type checkers. import sibling_module, not from . In your specific case, you are using the imported class to define an upper bound on the type variable. py, as it gets the Response object injected in initialized state. py Jun 7, 2023 · But if we try to import from our models module now, we'll have a problem because we haven't fully initialized the models module. Below is a short comparison of them Since you’re just using the ClassA import for a type hint, you can guard this import with typing. from . py Traceback (most recent call Nov 4, 2024 · This solves the problem of circular dependency between the modules within the same package. When using the import statement in Python, circular importing, a type of circular dependency, is produced. Jun 20, 2021 · from typing import List, TYPE_CHECKING from other_module import TypeIDoNeedAtRuntime if TYPE_CHECKING: from dangerous_circular_module import TypeIOnlyNeedForHints class AnotherClass from typing import TYPE_CHECKING if TYPE_CHECKING: from vertex import Vertex class Edge: def __init__(self, v1: Vertex, v2: Vertex): self. Also keep in mind, that when typing is used, the import needs to be at top level (either start or end of the file). TYPE_CHECKING: from typing import TYPE_CHECKING if TYPE_CHECKING: from project. ActionType import ActionType from classes. import_module() 関数を使用することです。この関数を使用すると、モジュールの名前を文字列として渡すことで、プログラムから動的にモジュールをインポートすることができます。 Mar 15, 2023 · Circular Import in Python. String literals such as toys:["ToyResponse"], this method still causes circular import errors because you are still importing the class to resolve the type. the documentation for this approach as mentioned above is in the mypy documentation as well as in pep-484 itself. But at the same time this scripts are difficult Nov 12, 2020 · You have a circular import. This tutorial explores comprehensive techniques for identifying, understanding, and resolving circular import problems, helping developers create more modular and efficient Python code. SQLAlchemy's typing features assume basic familiarity with Python typing. py file is involved in the circular import, but the issue is both rare, and probably a bug in the import implementation. SomeClass') -> None: a_var = arg # type: expensive_mod. For instance: # module_a. During this process, we always tend to import other modules from the package. In the (very) long term future, would the syntax. This can lead to problems in your code, as Python's import system can get confused when faced with circular dependencies. py needs to import SelectionLib. ABC class that describes the interface, then the concretions implement the interface and you don't import those. py from sqlalchemy import Column, Integer, ForeignKey from sqlalchemy. Oct 17, 2017 · The Python documentation also says that it is advisable to use import X, instead of other statements, such as from module import *, or from module import a,b,c. You can't do that. To avoid it: Oct 10, 2023 · The third and final common way to eliminate this import cycle is to merge the two modules. Let’s say I have a Director and an Actor. 때는 신나게 Slack bot을 개발하던 시점이었습니다. #1/4 from __future__ import annotations # this is important to have at the top from pydantic import BaseModel #2/4 class A(BaseModel): my_x: X # a pydantic schema from another file class B(BaseModel): my_y: Y # a pydantic schema from another file class C(BaseModel): my_z: int #3/4 Jul 18, 2022 · Some circular imports in Python are “real”, and cannot be resolved without moving where your objects are defined. If you don’t import it, you can use type hints as string. Apr 21, 2022 · In most cases using typing. For details, you have a look into PEP 563. In consequence it will not see objects created after import statement. py: Jul 30, 2020 · In Python typing, circular dependencies can be resolved with a forward reference: class A: b: "B" def __init__(self, b: "B"): self. TYPE_CHECKING constant as Dec 30, 2021 · もともとはPython 3. from my_module himport A. from typing import TYPE_CHECKING if TYPE_CHECKING: from mod1. Note annotations future-import (), alternatively you can enclose all names not available at runtime (imported under if TYPE_CHECKING) in quotes. Nov 19, 2024 · # I002: Missing required import: `from __future__ import annotations` from typing import TYPE_CHECKING if TYPE_CHECKING: from graph. c1 = c1 So the problem is that DataLib. Thankfully, there’s a trick to add circular imports for type hints without causing ImportErrors. py, you from . This would work well in code that is only using simple type hints that doesn’t need access to any of the functions in typing. Client import Client from classes. 一个circular import实例 之前遇到一个circular import的问题，项目文件结构大概如下： Feb 2, 2024 · Hello, I think I’m asking an obvious question, but maybe I’m missing something. 11. Jul 7, 2023 · In principle, solving the circular import problem for typing purposes is very simple. What occurs differently between "runtime" and "type checking"? Does the process of "type checking" mean code is not executed? Notes: This is not a circular import dependency problem so dependency injection isn't needed. The easiest solution is to merge this into a single module. annotations is not default in Python now; but it will become the default in Python 3. 1 복잡도가 상승하면서 별도 클래스나 모듈로 분리하는 요소가 많아지기 시작했죠. This is all good and well for a static type checker. A type expression is any expression that validly expresses a type. It could be much more succinct: from module_z import type A def foo(p0:A): Oct 25, 2024 · However, at runtime, TYPE_CHECKING will invariably be set to False so no circular import here. Action import Action from typing import List class Entity: """ The entities are added from the Game object """ def __init__(self, name: str, max_health: int,team: int Mar 11, 2024 · Specifically, you can set up the relationship members later (after class definition) in some other file, but then everywhere in the code, I'll have type-checkers like mypy shouting at me. py from module_b import func_b def func_a(): func_b() Apr 25, 2024 · In conclusion, effectively handling circular imports requires an understanding of Python’s import mechanism and your code’s architecture. py a. This is called a circular import or a dependency loop. The typing. – Mar 17, 2024 · Not necessarily, since the import is delayed, the circular dependency may now no longer be a circular dependency, since both modules have already been fully initialized, so it depends on at which point the runtime introspection happens. TYPE_CHECKING could be made a built-in name to allow for situations where typing would not have to be imported at all at runtime. py are created to achieve this: test1. Take these two files: May 15, 2024 · The Circular Imports in Python programming occur when two or more modules mutually depend on each at the same time forming a loop between them. In our case, it will be old_book_object: ‘Book’. py. Below code sample demonstrates it. This helps me use type hints without depending on circular dependencies Aug 16, 2023 · A circular import in Python is a situation where two or more Python modules are interdependent on each other, creating a loop or "circle" in the dependency graph. I can then import the base class(es) for type hints without importing the implementations, avoiding that type of issue Another piece of advice is have is to use typing. py already imports DataLib. /main. Use the ‘lazy’ module import feature when it is required. Circular imports are a common challenge in Python programming that can lead to complex and hard-to-debug dependency issues. 9. Circular dependency is the case when some modules depend on each other. May 13, 2021 · Python type hints: fix circular imports 2021-05-13. be a good solution? That is a statement ignored by python but read by the type-hinter as a normal import. SomeClass Nov 2, 2020 · 文章浏览阅读10w+次，点赞29次，收藏88次。使用Python编写稍大工程时，常遇到循环导入（circular import）问题。本文以Flask中的问题为例，介绍循环导入产生的原因，分析了import执行过程，指出要理解Python import工作原理，重新设计代码结构，保证单向引用，以解决该问题。 Sep 25, 2024 · Normal typing; doesnt work when a child import a parent. If we try to do something to that type and Python can’t perform the operation, it’ll tell us later on. Nov 21, 2023 · 他モジュールのクラスのインスタンスを受け取る、インスタンスのメソッドを呼ぶ場合は、循環参照ではありますが、circular importエラーは出ません。 Pythonの仕様によりimportせずとも受け取ったり呼べたりするからです。動的型付けの強み。 Mar 25, 2024 · Think of two pieces of code (let's call them A and B) that need each other to work. Ces techniques peuvent vous aider à écrire un code Python plus robuste et plus maintenable. Sometimes, classes need to talk to each other in both directions. Apr 7, 2021 · For such situations the typing module defines a constant, TYPE_CHECKING, that is considered True during type checking (or other static analysis) but False at runtime. TYPE_CHECKING can be seen as Python's alternative to C and C++'s header files. py and garage. Let’s start at the beginning. For example: example. Often the circular import statement only exists due to type hinting and are not used by python. It can create probl, Python Circular Imports Module: Solving Circular Import Problem, Python Tutorial Aug 27, 2021 · はじめに テスト駆動開発のjavaで書かれた部分をpythonで実装しているとき、 ImportError: cannot import name 'Money' from partially initialized module 'moneys. bar import Bar else: Bar = "Bar" # foo. And it kind of sucks. g. ) “Static Typing with Python” Type-checker-agnostic documentation written by the community detailing type system features, useful typing related tools and typing best practices. class1 import Class1 class Class2(object): def __init__(self, c1: "Class1"): self. You can try any of these above-mentioned ways to avoid circular dependency in Python. test1. py, and then tries to from . So, if your other module calls back to another module that is yet to initialize in __init__, it’ll throw a circular import. py module to import request. Python ImportError: Cannot Import Name Example. foo). TYPE_CHECKING special constant. authentication/models imports corporate/models, which imports corporate/models/section, which imports authentication/models. What does the Python Circular Erro Oct 23, 2024 · To mitigate these issues, Python offers two powerful tools: using if TYPE_CHECKING from the typing module and the from __future__ import annotations statement. Reference Links: Python 3 Type Hints Documentation; Real Python – Python Type Checking; Stack Overflow – Circular or Cyclic Imports in Python; Conclusion: Circular dependencies can be a common issue in large Python codebases. In general, data modeling frameworks like Pydantic and attrs have functionality to resolve forward references automatically. Aug 16, 2023 · Il existe plusieurs techniques permettant d'éviter les importations circulaires en Python, notamment l'utilisation d'importations absolues, l'utilisation de la fonction importlib. Jul 20, 2023 · Runtime circular imports are a symptom of a design problem. You can think of python code executing line by line, so when in a. But you probably don't want to do that. To ensure the high quality of your project and code, avoid circular imports through careful and thoughtful design of the application and its code. Jul 26, 2023 · 刚才只是语法检查时发生错误，现在仍然没有避免循环导入。 解决这个问题就需要消除两个文件互相 import。但实质上是不存在循环导入问题的，因为我仅仅是增加了方便静态分析的类型注解，对程序运行毫无影响。 Jan 23, 2023 · The problem started when I had two classes that needed to talk to each other. py において、「 A というクラスが型ヒントに利用されていますが、インポートされておらず名前がよくわからないよ import typing if typing. Sep 17, 2020 · 文章浏览阅读2. We would like to show you a description here but the site won’t allow us. py from typing import TYPE_CHECKING if TYPE_CHECKING: from b import B cla Dec 13, 2012 · But in that case, nothing you import will be importing you. Apr 9, 2010 · >> :) fair enough. Mar 14, 2024 · With PEP 649 impending, I have some concerns that the tension between static-only and runtime type annotations may get worse. I usually have something like a base. that would result in a circular import Mar 9, 2010 · To avoid having to alter every module, you could stick your import-tracking functionality in a import hook, or in a customized __import__ you could stick in the built-ins -- the latter, for once, might work better, because __import__ gets called even if the module getting imported is already in sys. Position import Position from classes. Since I started using type hinting more, I noticed that it is easier to get into circular import Jan 8, 2025 · Circular imports happen when two or more Python modules depend on each other’s definitions. Types of Circular Import Problems. So we have a problem. " Pycycle is an experimental project that aims to help python developers fix their circular dependencies problems. 1w次，点赞14次，收藏31次。在python中常常会遇到循环import即circular import的问题，今天主要给大家介绍了关于Python中循环引用（import）失败的解决方法，文中通过示例代码介绍的非常详细，需要的朋友可以参考借鉴。 Apr 3, 2023 · you can use TYPE_CHECKING. In Java and other strong typed languages such issues appear quite often and have some "standard" solutions. Introduction. 10などでは自身のクラスをそのクラスのメソッドに対して型アノテーションをする場合from __future__ import annotationsなどの指定が必要（Python 3. Circular imports can lead to various issues, including The typing module has a variable TYPE_CHECKING that allows the compiler to know when to not import another module in actual runtime. models' (most likely due to a circular import) The solution is using typing. Protocol version is to a lighter weight version of the interface idea that formalizes Feb 2, 2024 · Solve Importerror: Cannot Import Name In Python. Circular import creates situation when importing module uses imported one with partially executed code. Dec 23, 2019 · Resolving circular imports of Python type hints [duplicate] Ask Question maintain type hinting, and run into a circular import error? python; circular-dependency; Jan 8, 2018 · I came across this issue when those classes are set in different files (a. Python: circular imports needed for type checking. money' (most likely due to a circular import) というエラーに遭遇しました。 これは循環参照と呼ばれるものであり、 # money. Map import Map from classes. The value of the constant Mar 4, 2024 · A Python circular import can occur when two or more modules mutually depend on each other. Mar 17, 2024 · Just for reference, runtime resolvability and cyclic imports are a known thing, and the current “best practice” involves not having a circular import even within TYPE_CHECKING Not much else to add, this topic is retreading ground other people have covered in multiple ways, and there’s good reasons why lazy importing wasn’t accepted in general, why those who have a need for it have from __future__ import annotations from typing import TYPE_CHECKING if TYPE_CHECKING: # pylint: disable = ungrouped-imports from module_z import A def foo(p0:A): I know I use it a lot - literally every one of my python files. Mar 23, 2021 · With the acceptance of PEP 563 and its soon-to-be-default status, I was thinking that maybe typing. The Director tells the Actor to do_action(). py: from test2 import Class2 class Class1: obj = Class2() test2. These changes will stop the circular import while also allowing your IDE/tooling to find Apr 13, 2024 · The type hints allow the functions to reference each other without causing import errors. Sep 24, 2021 · What causes circular import problems in __init__. Consider the following toy example Nov 28, 2020 · I am writing some python code with type hinting and am facing a circular dependency problem with mypy. Type expressions are always Jul 31, 2021 · __future__. The following example is made up, but mostly behaves like the original problem. You may also see many code-bases using deferred importing even if there isn't a circular dependency, which speeds up the startup time, so this is not considered bad practice at all Nov 15, 2022 · 通过python+selenium去爬取goodreads上一本书的评论，由于goodreads的评论是一页加载所有内容，不断点load more，就不断在该页面增加内容，在加载到3000-5000条评论时，页面就会崩溃，用的edge，内存设置的无限制。 Dec 3, 2017 · 기본 지식. These modules' dependency on each other often results in the program getting stuck and generating circular import errors. Some of the below status quo solutions also rely on TYPE_CHECKING, which is currently only safe by convention, not by specification, see related discussion here: Specify `TYPE Apr 7, 2020 · # pyright: strict from classes. , import A then foo = A. Example of Circular Import. A particular kind of circular dependency is Python Circular Imports. raej xwgvbg enkh ffadmvi qlilnf zivb wzyk cwgxvk ocmibty upuww sgiyism qxh pdqvmogk xtxd caz