Class Reference pythonEnv

Manages the user-local Python virtual environment for LayoutScript. More...

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Detailed Description

The pythonEnv class controls the Python environment used for external and in-process LayoutScript execution. By default a virtual environment is kept under ~/LayoutEditor/python_env. Packages can be installed with pip without root privileges.

If the LayoutEditor was started inside an already activated virtual environment (VIRTUAL_ENV is set), that environment is used instead and ~/LayoutEditor/python_env is not created.

LayoutScript and _LayoutScript are shipped with the LayoutEditor installation. They must not be installed with pip.

This class was introduced with release 20260718.

Member Function Documentation

static string pythonEnv::path()

Returns: the active environment root (VIRTUAL_ENV or ~/LayoutEditor/python_env). (introduced with release 20260718)

static string pythonEnv::pythonExecutable()

Returns: the Python executable inside the active environment. (introduced with release 20260718)

static string pythonEnv::sitePackagesPath()

Returns: the site-packages directory of the active environment. (introduced with release 20260718)

static bool pythonEnv::isExternallyActivated()

Returns: true if the LayoutEditor was started with VIRTUAL_ENV set. (introduced with release 20260718)

static bool pythonEnv::ensure()

Creates the managed virtual environment under ~/LayoutEditor/python_env if it does not exist yet. Does nothing when an external virtual environment is already active. Returns: true on success. (introduced with release 20260718)

#!/usr/bin/layout
#name=ensure python env
#help=create ~/LayoutEditor/python_env if needed

int main(){
  if (pythonEnv::ensure()) {
    layout->showStatus("Python env: "+pythonEnv::path());
  } else {
    layout->showMessage("pythonEnv",pythonEnv::lastOutput());
  }
  return 0;
}

static bool pythonEnv::isPackageInstalled(string name)

Returns: true if the pip package name is installed in the active environment. (introduced with release 20260718)

static int pythonEnv::pipInstall(string package)

Installs package with pip into the active environment. Returns: the process exit code (0 on success). Refuses LayoutScript / _LayoutScript (shipped with LayoutEditor, not via PyPI). (introduced with release 20260718)

#!/usr/bin/layout
#name=pip install example
#help=install a Python package into the LayoutEditor env

int main(){
  pythonEnv::ensure();
  if (pythonEnv::pipInstall("requests")!=0) {
    layout->showMessage("pipInstall failed",pythonEnv::lastOutput());
  }
  return 0;
}

static int pythonEnv::pipUninstall(string package)

Uninstalls package with pip. Returns: the process exit code. (introduced with release 20260718)

static string pythonEnv::pipList()

Returns: the output of pip list. (introduced with release 20260718)

static int pythonEnv::runModule(string module,stringList args=stringList())

Runs python -m module with args in the active environment. Returns: the process exit code. Use this to call Python CLI tools (for example later volare). (introduced with release 20260718)

#!/usr/bin/layout
#name=run python module
#help=example for pythonEnv::runModule

int main(){
  pythonEnv::ensure();
  stringList args;
  // args.append("--help");
  int code=pythonEnv::runModule("pip",args);
  layout->showMessage("runModule",pythonEnv::lastOutput());
  return code;
}

static string pythonEnv::lastOutput()

Returns: stdout/stderr of the last pip / venv / python -m invocation. (introduced with release 20260718)