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Questions tagged [pylance]

Pylance is an extension for Visual Studio Code that provides a language server for Python. When applying this tag to your question, consider also tagging it with [visual-studio-code] and/or [python].

Pylance is a language server to support the core Python extension for Visual Studio Code. Its aim is to help developers write Python code better and faster by providing auto-imports, semantic highlighting, built-in reporting of warnings and errors, strict type-checking, and method signatures with type information when displaying the popup Intellisense documentation.

It was first introduced in a post on Microsoft's Python development blog: Announcing Pylance: Fast, feature-rich language support for Python in Visual Studio Code:

To deliver an improved user experience, we’ve created Pylance as a brand-new language server based on Microsoft’s Pyright static type checking tool. Pylance leverages type stubs (.pyi files) and lazy type inferencing to provide a highly-performant development experience. Pylance supercharges your Python IntelliSense experience with rich type information, helping you write better code, faster. The Pylance extension is also shipped with a collection of type stubs for popular modules to provide fast and accurate auto-completions and type checking.

It was made available starting VS Code 1.49 (2020.8.0 (12 August 2020) release).

  1. Expose Pylance setting in python.languageServer. If Pylance extension is not installed, prompt user to install it. (#13122)

Installation is straightforward:

  1. Install the Pylance extension
  2. Configure your settings.json file 
    "python.languageServer": "Pylance",
  3. Open a .py file and the extension should activate

For more information:

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VSCode Pylance changed text color

I just installed Pylance on VisualStudioCode, my theme is OneDarkPro. I can manually set the text color with editor.semanticTokenColorCustomizations in settings.json but I wonder if there is a way to simply keep my previous text color. This is how…
Furin
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VSCode settings for Pylance

I am running Vscode with the following components: Version: 1.51.1 (user setup) Commit: e5a624b788d92b8d34d1392e4c4d9789406efe8f Date: 2020-11-10T23:34:32.027Z Electron: 9.3.3 Chrome: 83.0.4103.122 Node.js: 12.14.1 V8: 8.3.110.13-electron.0 OS:…
Jonathan
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mypy slow when using vscode's python extension

When enabling mypy in vscode ("python.linting.mypyEnabled": true,), then any manual mypy commands become very slow and CPU intensive (10s before vs 3min after). It seems like the two mypy processes should be independent, or even aid each other…
JBSnorro
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Pylance - Type of pandas method is partially unknown

If I try to validate code that uses pandas methodes with pylance in strict mode, I get a validation error. import pandas as pd ser: pd.Series[float] = pd.Series([.1, .2, .5, .3]) print(ser.max()) Pylance in strict mode returns the error: Type of…
AlexanderP
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VS Code problem when using magic commands in Jupyter notebooks: "Expected expression Pylance"

I'm playing around with Python's and NumPy's methods to compare their performance: import numpy as np massive_array = np.random.random(100000) %timeit sum(massive_array) # Python's sum() %timeit np.sum(massive_array) # NumPy's np.sum() Which…
ale917k
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Python typing: do stubs take precedence over library sources?

I'm splitting my code into multiple packages, which are installable via PyPI. Then these packages are used in a child package, where I want type information from "library" packages to be fully used. In order to have complete type checking, I'd like…
Boschie
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How to disable all stylistic warnings in Pylance in VS Code?

I like the linting Pylance does in VS Code on my macbook, but for some strange reason it insists on making my life difficult on my windows work-computer. The problems section shows 99+ Problems but they are all of a stylistic nature. Like that…
Gundheri
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How can I type hint SQLAlchemy Queries?

I'm using Pylance (with type hints powered by PyRight) in VSCode, and have the following function: def sample(session: sqlalchemy.orm.Session) -> sqlalchemy.orm.query.Query: return session.query((MyModel) When looking at Pylance's type…
T. McManus
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How to type hint a tuple variable in python?

In python I have a an object data that maybe any object it will be. In vscode v1, v2 = data # type: str, str sentence I want v1, v2 will popup str method. In vscode v1, v2 = data # type: dict, set sentence I want v1, v2 will popup dict, set…
jett chen
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VSCode + Pylance: Class attributes recognized but no autocomplete available

I've recently installed Pylance as python language server on VSCode. I'm building an app with PyQt5. In the script under question, I'm inheriting a UI python script automatically generated by pyqt5 uic. listProfiles is a QListView object generated…
Buzz
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How to resolve 'Import openai could not be resolved' error (pylance) with pip install command?

I feel like I'm asking a dumb question, but I've looked at multiple StackOverflow threads and articles online already but still haven't fixed my problem. I'm trying to use the OpenAI Python library to train a new model, but even after running…
VerisimilitudeX
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Polymorphism in Callablle under python type checking (Pylance)

For my code I have an aggregate class that needs a validation method defined for each of the subclasses of base class BaseC, in this case InheritC inherits from BaseC. The validation method is then passed into the aggregate class through a register…
ted
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Achieving interface without inheritance in Python

I have a sorted linked list class SortedLinkedList: # ... def insert(self, value: int): # ... if node.value > value: self.add_before(node, value) # ... I would like to generalize the type of values that a…
Michael Moreno
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Ignore Pylance missing imports

I'm trying to modify my settings.json file for VSCode to ignore missing imports for my own scripts. As i've learnt I have to set "python.analysis.useImportHeuristic" to true. Code says it is an unknown configuration setting but as long as I've…
aarribas12
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How to ignore Pylance type checking on notebooks?

I have a python project in which I have python files and notebooks. I use strict typing in my project but I would like to remove it only on notebooks. I use VScode with setting: "python.analysis.typeCheckingMode": "strict" I know how to ignore type…
Vince M
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