semvec/pypi-packages huggingface dataset:
sharedfile 0.8
Cross-platform shared file open with share flags
License: Apache-2.0

# Sharedfile

**Easily let multiple Python processes read from and write to the same file at once.**

A simple, cross-platform Python extension that makes it safe and easy for different processes to open and use the same file at the same timeâ€”perfect for logging, sharing data, or coordinating between programs.

## Features

- Super simple API: `sharedfile.open(path, mode="r", share="rw")`
- Works on Windows and POSIX (Linux/macOS)
- Lets you control how files are shared (Windows)
- Uses advisory locking for safe sharing on POSIX systems
- Feels just like Pythonâ€™s built-in `open`

## Installation

Install directly from PyPI:

```sh
pip install sharedfile
```

[View on PyPI](https://pypi.org/project/sharedfile/)

Or build and install manually:

```sh
python setup.py build
python setup.py install
```

## Usage Example

Let two processes write to and read from the same file:

```python
import multiprocessing
import time
import sharedfile

def writer():
    with sharedfile.open("shared_test.txt", mode="w", share="rw") as f:
        for i in range(5):
            line = f"Writer line {i}\n"
            f.write(line)
            f.flush()
            print(f"[Writer] wrote: {line.strip()}")
            time.sleep(1)

def reader():
    time.sleep(0.5)  # Let writer start first
    with sharedfile.open("shared_test.txt", mode="r", share="rw") as f:
        for _ in range(5):
            f.seek(0)
            content = f.read()
            print(f"[Reader] read:\n{content.strip()}")
            time.sleep(1)

if __name__ == "__main__":
    p1 = multiprocessing.Process(target=writer)
    p2 = multiprocessing.Process(target=reader)
    p1.start()
    p2.start()
    p1.join()
    p2.join()
```

## API

```python
sharedfile.open(path, mode="r", share="rw")
```

- `path`: File path.
- `mode`: File mode (`"r"`, `"w"`, `"a"`, `"r+"`, etc.).
- `share`: (Windows only) Control who else can access the file:
    - `"r"`: Let others read
    - `"w"`: Let others write
    - `"rw"`: Let others read and write
    - (Ignored on POSIX; uses advisory locking)

Returns: A Python file-like object.

## Platform Details

- **Windows:** Uses native Win32 APIs for explicit read/write sharing.
- **POSIX:** Uses advisory `fcntl` locking for cooperative sharing.

## License

Licensed under the Apache License, Version 2.0. See [LICENSE](./LICENSE) for details.

## Author

[Jan Bremec](https://github.com/JanBremec)