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Welcome to the PyCTools Wiki

PyCTools is a lightweight set of native DLLs and Python bindings for process inspection, memory analysis, and system metric collection on Windows.

This wiki serves as the official documentation hub. Whether you're a C developer building your own DLLs, a Python user leveraging the wrappers, or just curious how the system works under the hood — you're in the right place.

What You'll Find Here:

• DLL Internals & Discovery How the processInspect and hRng DLLs are structured, built, and dynamically located.

• Python Usage & Examples Step-by-step guides for using the wrapper classes, session handling, and metric querying.

• C Code Explanations Detailed look into the native code powering the DLLs, from memory APIs to performance counters.

⚙ Whether you're downloading prebuilt binaries or compiling from source — this wiki will help you understand how it all fits together.

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DLL Discovery and bin/ Directory

Important

Starting from v0.2.0-beta the script now purely checks bin/ inside the pyCTools directory!

In short ignore everything on the bottom

DLL Output Structure

Compiled DLLs are placed in the bin/ directory, organized by architecture:

dist/
  x64/
    hRng_x64.dll
    processInspect_x64.dll
    ...
  x86/
    hRng_x86.dll
    processInspect_x86.dll
    ...

• x64/: DLLs for 64-bit Python and applications
• x86/: DLLs for 32-bit Python and applications

How Python Finds the DLLs

Both hwrng and processInspect automatically search for the correct DLL based on your Python interpreter's architecture. Locations that are searched are:

• ./bin/{arch}/{dll}_{arch}.dll (relative to the Python library file)

Where {arch} is x64 or x86 and {dll} is the mentioned/provided dll per library.

If the DLL is not found, a FileNotFoundError is raised.

Building the DLLs

1. Open PowerShell and run:

   cd ./tool/
   compilerHelper.ps1

2. Choose the .c source files you want to compile.

3. The script will compile for both x86 and x64 architectures, placing the output in:

   • pyCTools/bin/x86 (32-bit builds)
   • pyCTools/bin/x64 (64-bit builds)

Important

The build process uses cl.exe from the MSVC toolchain in Visual Studio, so make sure it’s installed and available in your PATH.

Note

• Each compiled source produces four files per architecture: .dll, .exp, .lib, and .obj.

• Only the .dll is needed by the Python library.

• DLL filenames include an architecture suffix:

  • Example: hRng_x86.dll, hRng_x64.dll.

Troubleshooting

• If you get DLL not found errors, check that the correct DLLs exist in the expected bin/{arch} folders.
• Ensure you are using the correct Python architecture (x64 or x86) for the DLLs present.