Call python

Call python command:

tasks.register('cmd', PythonTask) {
    command = "-c print('sample')"
}

called: python -c print('sample') on win and python -c exec("print('sample')") on *nix (exec applied automatically for compatibility)

Call multi-line command:

tasks.register('cmd', PythonTask) {
    command = '-c "import sys; print(sys.prefix)"'
}

called: python -c "import sys; print(sys.prefix)" on win and python -c exec("import sys; print(sys.prefix)") on *nix

Note

It is important to wrap script with space in quotes (otherwise parser will incorrectly parse arguments).

String command is used for simplicity, but it could be array/collection of args:

tasks.register('script', PythonTask) { 
    command = ['path/to/script.py', '1', '2'] 
}

Pip module command

tasks.register('mod', PythonTask) {
    module = 'sample' 
    command = 'mod args'
}

called: python -m sample mod args

Script

tasks.register('script', PythonTask) { 
    command = 'path/to/script.py 1 2'
}

called: python path/to/script.py 1 2 (arguments are optional, just for demo)

Command parsing

When command passed as string it is manually parsed to arguments array (split by space):

• Spaces in quotes are ignored: "quoted space" or 'quoted space'
• Escaped spaces are ignored: with\\ space (argument will be used with simple space then - escape removed).
• Escaped quotes are ignored: "with \\"interrnal quotes\\" inside". But pay attention that it must be 2 symbols \\" and not \" because otherwise it is impossible to detect escape.

To view parsed arguments run gradle with -i flag (enable info logs). In case when command can't be parsed properly (bug in parser or unsupported case) use array of arguments instead of string.

Environment variables

By default, executed python can access system environment variables (same as System.getenv()).

To declare custom (process specific) variables:

tasks.register('sample', PythonTask) {
       command = "-c \"import os;print('variables: '+os.getenv('some', 'null')+' '+os.getenv('foo', 'null'))\""
       environment 'some', 1
       environment 'other', 2
       environment(['foo': 'bar', 'baz': 'bag'])
}

Map based declaration (environment(['foo': 'bar', 'baz': 'bag'])) does not remove previously declared variables (just add all vars from map), but direct assignment environment = ['foo': 'bar', 'baz': 'bag'] will reset variables.

System variables will be available even after declaring custom variables (of course, custom variables could override global value).

Note

Environment variable could also be declared in extension to apply for all python commands: python.environment 'some', 1 (if environments declared both globally (through extension) and directly on task, they would be merged)

Non-default python

Python task would use python selected by checkPython task (global or detected virtualenv). If you need to use completely different python for some task, then it should be explicitly stated with useCustomPython property.

For example, suppose we use virtual environment, but need to use global python in one task:

tasks.register('script', PythonTask) {
    // global python (it would select python3 automatically on linux)
    pythonPath = null
    // force custom python for task
    useCustomPython = true
    command = ['path/to/script.py', '1', '2'] 
}

Additional property (useCustomPython) is required because normally task's pythonPath is ignored (an actual path is selected by checkPython task)