listdictLiteralCallableTypedDictTypeVar, Generic)TypeVarGenericProtocolFinalAnnotatedTypeAliasTypeGuard)TypeGuardcollections.abcIterablepylyzer is a static code analyzer / language server for Python, written in Rust.
pip install pylyzer\ncargo install pylyzer --locked\ngit clone https://github.com/mtshiba/pylyzer.git\ncargo install --path . --locked\nMake sure that cargo/rustc is up-to-date, as pylyzer may be written with the latest language features.
On average, pylyzer can inspect Python scripts more than 100 times faster than pytype and pyright 1. This is largely due to the fact that pylyzer is implemented in Rust.
While pytype/pyright's error reports are illegible, pylyzer shows where the error occurred and provides clear error messages.
"},{"location":"#pylyzer_1","title":"pylyzer \ud83d\ude03","text":""},{"location":"#pyright","title":"pyright \ud83d\ude43","text":"pylyzer as a language server supports various features, such as completion and renaming (The language server is an adaptation of the Erg Language Server (ELS). For more information on the implemented features, please see here).
"},{"location":"#vscode-extension","title":"VSCode extension","text":"You can install the VSCode extension from the Marketplace or from the command line:
code --install-extension pylyzer.pylyzer\nRuff, like pylyzer, is a static code analysis tool for Python written in Rust, but Ruff is a linter and pylyzer is a type checker & language server. pylyzer does not perform linting, and Ruff does not perform type checking.
"},{"location":"#how-it-works","title":"How it works","text":"pylyzer uses the type checker of the Erg programming language internally. This language is a transpiled language that targets Python, and has a static type system.
pylyzer converts Python ASTs to Erg ASTs and passes them to Erg's type checker. It then displays the results with appropriate modifications.
"},{"location":"#limitations","title":"Limitations","text":"pylyzer's type inspector only assumes (potentially) statically typed code, so you cannot check any code uses reflections, such as exec, setattr, etc.
pylyzer (= Erg's type system) has its own type declarations for the Python standard APIs. Typing of all APIs is not complete and may result in an error that such an API does not exist.
Since pylyzer's type checking is conservative, you may encounter many (possibly false positive) errors. We are working on fixing this, but if you are concerned about editor errors, please turn off the diagnostics feature.
listdicttupletypingUnionOptionalLiteralCallableTypedDictTypeVar, Generic)ProtocolFinalAnnotatedTypeAliasTypeGuard)collections.abcIterableIteratorMappingSequencetyping.cast)is, isinstance)1 The performance test was conducted on MacBook (Early 2016) with 1.1 GHz Intel Core m3 processor and 8 GB 1867 MHz LPDDR3 memory.\u21a9
"},{"location":"editor/","title":"Editor integrations","text":""},{"location":"editor/#vscode","title":"VSCode","text":":MasonInstall pylyzer in Neovim.If you use LunarVim, no setup is required. Just install pylyzer and you are good to go.
"},{"location":"errors/errors/","title":"Pylyzer-specific errors","text":""},{"location":"errors/errors/#e0001-reassignment-of-a-function-referenced-by-other-functions","title":"E0001: Reassignment of a function referenced by other functions","text":"def g(): return f()\n\ndef f(): return 1\ndef f(): return \"a\" # E0001: Reassignment of a function referenced by other functions\n\nprint(g())\n__init__ doesn't have a first parameter named self","text":"class C:\n def __init__(a): pass # E0002\n__init__ as a member variable","text":"class C:\n __init__ = 1 # E0003\ndef f(x): return x\n\nf(1) # W0188: UnusedWarning: the evaluation result of the expression (: {1, }) is not used\nLaunch as a language server.
"},{"location":"options/options/#-dump-decl","title":"--dump-decl","text":"Dump a type declarations file (d.er) after type checking.
$ pylyzer --dump-decl test.py\nStart checking: test.py\nAll checks OK: test.py\n\n$ ls\ntest.py test.d.er\nCheck code from the command line.
$ pylyzer -c \"print('hello world')\"\nStart checking: string\nAll checks OK: string\npyproject.toml options","text":""},{"location":"options/pyproject/#toolpylyzerpythonpath","title":"tool.pylyzer.python.path","text":"Path to the Python interpreter to use. If not set, the default Python interpreter will be used.
[tool.pylyzer.python]\npath = \"path/to/python\"\npylyzer is a static code analyzer / language server for Python, written in Rust.
pip install pylyzer\ncargo install pylyzer --locked\ngit clone https://github.com/mtshiba/pylyzer.git\ncargo install --path . --locked\nMake sure that cargo/rustc is up-to-date, as pylyzer may be written with the latest language features.
On average, pylyzer can inspect Python scripts more than 100 times faster than pytype and pyright 1. This is largely due to the fact that pylyzer is implemented in Rust.
While pytype/pyright's error reports are illegible, pylyzer shows where the error occurred and provides clear error messages.
"},{"location":"#pylyzer_1","title":"pylyzer \ud83d\ude03","text":""},{"location":"#pyright","title":"pyright \ud83d\ude43","text":"pylyzer as a language server supports various features, such as completion and renaming (The language server is an adaptation of the Erg Language Server (ELS). For more information on the implemented features, please see here).
"},{"location":"#vscode-extension","title":"VSCode extension","text":"You can install the VSCode extension from the Marketplace or from the command line:
code --install-extension pylyzer.pylyzer\nRuff, like pylyzer, is a static code analysis tool for Python written in Rust, but Ruff is a linter and pylyzer is a type checker & language server. pylyzer does not perform linting, and Ruff does not perform type checking.
"},{"location":"#how-it-works","title":"How it works","text":"pylyzer uses the type checker of the Erg programming language internally. This language is a transpiled language that targets Python, and has a static type system.
pylyzer converts Python ASTs to Erg ASTs and passes them to Erg's type checker. It then displays the results with appropriate modifications.
"},{"location":"#limitations","title":"Limitations","text":"pylyzer's type inspector only assumes (potentially) statically typed code, so you cannot check any code uses reflections, such as exec, setattr, etc.
pylyzer (= Erg's type system) has its own type declarations for the Python standard APIs. Typing of all APIs is not complete and may result in an error that such an API does not exist.
Since pylyzer's type checking is conservative, you may encounter many (possibly false positive) errors. We are working on fixing this, but if you are concerned about editor errors, please turn off the diagnostics feature.
listdicttupletypingUnionOptionalLiteralCallableTypedDictTypeVarGenericProtocolFinalAnnotatedTypeAliasTypeGuardcollections.abcIterableIteratorMappingSequencetyping.cast)is, isinstance)1 The performance test was conducted on MacBook (Early 2016) with 1.1 GHz Intel Core m3 processor and 8 GB 1867 MHz LPDDR3 memory.\u21a9
"},{"location":"editor/","title":"Editor integrations","text":""},{"location":"editor/#vscode","title":"VSCode","text":":MasonInstall pylyzer in Neovim.If you use LunarVim, no setup is required. Just install pylyzer and you are good to go.
"},{"location":"errors/errors/","title":"Pylyzer-specific errors","text":""},{"location":"errors/errors/#e0001-reassignment-of-a-function-referenced-by-other-functions","title":"E0001: Reassignment of a function referenced by other functions","text":"def g(): return f()\n\ndef f(): return 1\ndef f(): return \"a\" # E0001: Reassignment of a function referenced by other functions\n\nprint(g())\n__init__ doesn't have a first parameter named self","text":"class C:\n def __init__(a): pass # E0002\n__init__ as a member variable","text":"class C:\n __init__ = 1 # E0003\ndef f(x): return x\n\nf(1) # W0188: UnusedWarning: the evaluation result of the expression (: {1, }) is not used\nLaunch as a language server.
"},{"location":"options/options/#-dump-decl","title":"--dump-decl","text":"Dump a type declarations file (d.er) after type checking.
$ pylyzer --dump-decl test.py\nStart checking: test.py\nAll checks OK: test.py\n\n$ ls\ntest.py test.d.er\nCheck code from the command line.
$ pylyzer -c \"print('hello world')\"\nStart checking: string\nAll checks OK: string\npyproject.toml options","text":""},{"location":"options/pyproject/#toolpylyzerpythonpath","title":"tool.pylyzer.python.path","text":"Path to the Python interpreter to use. If not set, the default Python interpreter will be used.
[tool.pylyzer.python]\npath = \"path/to/python\"\n