strip-hints: Python Type Hint Stripping Utility

Warnings

• gotcha Using options like `--strip-nl` (also strip non-logical newline tokens) or `--to-empty` (map removed code to empty strings) can alter the original line and column numbers. This can make debugging the stripped code harder by breaking correspondence with the original source.
  Fix: Avoid `--strip-nl` and `--to-empty` if exact line/column number correspondence is critical for debugging. The default behavior attempts to preserve these.
• gotcha The `--no-equal-move` command-line option prevents the program from adjusting annotated assignments that include newlines in their type hints. If such a situation occurs with this option enabled, it will raise an exception rather than attempting a syntactically correct transformation.
  Fix: Unless you specifically need to disallow the transformation, avoid using `--no-equal-move`. If an exception occurs, remove this flag or refactor your type hints to avoid newlines in annotated assignments.
• gotcha The library allows disabling stripping for specific code sections using `# strip-hints: off` and re-enabling with `# strip-hints: on`. Accidentally leaving these directives in or misplacing them can lead to unexpected behavior where hints are either retained or stripped in unintended areas.
  Fix: Carefully manage `# strip-hints: off` and `# strip-hints: on` directives, ensuring they are correctly placed and removed when no longer needed.
• deprecated The primary use case of `strip-hints` was originally for Python 2 compatibility (developing with Python 3 hints, running on Python 2). Python 2 is no longer maintained, and the library is no longer tested against it. The `install_import_hook` mechanism also uses the `imp` module, which is deprecated for Python 3. Users should target Python 3.
  Fix: Assume Python 3 as the target environment. If using `install_import_hook`, be aware of the underlying deprecated `imp` module.
• gotcha Stripping type hints removes runtime metadata. If other tools or frameworks in your ecosystem rely on runtime inspection of `__annotations__` or `typing.get_type_hints` (e.g., for dependency injection, API schema generation, or validation), using `strip-hints` will remove this crucial information, potentially causing runtime errors or unexpected behavior in those tools.
  Fix: Understand that `strip-hints` fundamentally alters the runtime availability of type annotations. Only use it when downstream consumers of the code do not require runtime type information, or if that information is recreated/managed by another mechanism.

Install

• pip install strip-hints Install from PyPI

Imports

• strip_string_hints

  from strip_hints import strip_string_hints

• strip_file_hints

  from strip_hints import strip_file_hints

• install_import_hook

  from strip_hints.import_hooks import install_import_hook

  Used for automatic stripping on import. Relies on the deprecated `imp` module for Python 3 and is not recommended for new Python 3 projects.

Quickstart

Demonstrates how to use `strip_string_hints` for in-memory string processing and `strip_file_hints` for processing Python files. The `strip_file_hints` function can output to stdout or a specified file.

import os
from strip_hints import strip_string_hints, strip_file_hints

# Example 1: Stripping hints from a string
code_with_hints = """
def greet(name: str) -> str:
    return f"Hello, {name}"
"""
stripped_code = strip_string_hints(code_with_hints)
print("--- Stripped String ---")
print(stripped_code)

# Example 2: Stripping hints from a file (creating a dummy file first)
file_content = """
# my_module.py
def add(a: int, b: int) -> int:
    return a + b

def subtract(x: float, y: float) -> float:
    return x - y
"""

with open("my_module_with_hints.py", "w") as f:
    f.write(file_content)

output_filename = "my_module_stripped.py"

# Strip hints and write to a new file
strip_file_hints("my_module_with_hints.py", outfile=output_filename)

print("\n--- Stripped File Content (my_module_stripped.py) ---")
with open(output_filename, "r") as f:
    print(f.read())

# Clean up dummy files
os.remove("my_module_with_hints.py")
os.remove(output_filename)