pymem

pymem is a lightweight Python library designed for interacting with the memory of running processes on Windows. It provides simple functions for reading and writing memory, enumerating modules, and searching for byte patterns. The library was created to aid developers and hobbyists in tasks such as automated testing, game hacking, or reverse engineering, where direct access to a process’s memory space is required.

The project was first released in 2018 by a contributor known as “FishQA,” and it has since evolved to support both 32‑bit and 64‑bit applications. PyPI hosts the package under the name pymem, and the source code is available on GitHub under the MIT license. PyMem depends on the standard Python libraries and the pywin32 package for Windows API bindings, making it easy to install via pip.

Core features include functions to open a process by PID or name, read and write integers, floats, strings, and arbitrary byte sequences, and obtain the base address of loaded modules. The find() routine implements pattern scanning, which is frequently used to locate specific code or data sections. While the library is versatile, it abstracts no protection mechanisms—attempting to modify protected memory may trigger access violations or antivirus detection.

Because pymem manipulates process memory, its use touches on legal and ethical considerations. Modifying the memory of software without explicit permission can violate End‑User License Agreements or local laws, and often disrupts normal operation of the target application. Therefore, developers are advised to use the library only within the bounds of applicable regulations and with explicit consent from the owners of the target process.