asottile/pyupgrade
Pyupgrade
pyupgrade is a static code modernizer and syntax upgrader for Python. It automatically rewrites source code to implement modern language features and syntax based on a specified target version.
The tool focuses on removing technical debt by deleting deprecated imports, compatibility shims, and obsolete version-specific conditional blocks. It also refactors type annotations to use current standards, such as simplified generic aliases and union operators.
Its capability surface includes updating standard library usage, optimizing built-in function calls, and converting verbose collection constructors or string formatting into concise modern equivalents. These transformations are performed via a target-versioned rule engine that preserves original formatting and comments.
Features
- Python Syntax Modernizers - Automatically rewrites Python source code to implement modern language features and syntax based on a specified target version.
- Python Code Modernizers - Removes technical debt by deleting deprecated imports, compatibility shims, and obsolete version-specific conditional blocks.
- Dead Code Removal - Automatically deletes obsolete imports, encoding comments, and version-specific conditional blocks that are no longer needed.
- Type Hint Refactoring - Refactors type annotations to use modern standards such as simplified generic aliases and union operators.
- Language Version Targeting - Executes specific transformation rules based on a user-defined target Python version to ensure language compatibility.
- Type Annotation Modernization - Updates Python type hinting syntax by removing quoted annotations and applying simplified generic aliases.
- Type Annotation Refactoring - Updates Python typing syntax to use modern standards such as built-in collection types and union operators.
- Python Refactoring Libraries - Provides automated refactoring of outdated type hinting syntax into modern generic aliases and union operators.
- Structural Pattern Matching - Identifies outdated code sequences and replaces them with modern equivalents through precise tree-node substitution.
- Compatibility Shim Removal - Deletes obsolete future imports, compatibility library calls, and version check blocks no longer required for the target version.
- Python Code Modernization - Updates legacy Python source code to use newer language features and syntax based on a target version.
- Python Syntax Optimization - Replaces verbose library calls and outdated string formatting with concise and efficient modern Python equivalents.
- Python Technical Debt Reduction - Removes deprecated imports, version compatibility shims, and obsolete code blocks no longer needed in newer environments.
- Concrete Syntax Tree Transformations - Implements transformations on concrete syntax trees to ensure that original source formatting and comments are preserved during rewriting.
- AST Transformation Tools - Uses a concrete syntax tree to apply precise structural changes while preserving formatting and comments.
- Multi-Pass Rewriting - Employs sequential transformation cycles to resolve complex, interdependent syntax upgrades in a single execution.
- Deprecated Import Normalization - Updates outdated module imports and replaces deprecated aliases with current standard library paths.
- Standard Library API Migration - Replaces deprecated function aliases and outdated argument patterns with current Python standard library equivalents.
- Standard Library API Simplification - Cleans up common standard library API usage to reduce verbosity and improve code readability.
- String Formatting Modernization - Transforms printf-style and method-based strings into modern formatted string literals or simplified specifiers.
- Python Literal Syntax Enforcement - Enforces the use of idiomatic Python literal syntax over verbose constructor calls for sets and dictionaries.
- Code Refactoring - Automatically updates syntax to use modern language features.
