Wraps a block in a Python virtualenv. Any pysh or pybat steps executed within the block,
are executed using the virtualenv specified
Example:
withPythonEnv('python3') {
pysh 'python --version'
}
The argument supplied to withPythonEnv is the name of the virtualenv to make available to any
pysh or pybat steps called within the block.
Initially, withPythonEnv tries to match the string passed to it to a tool name. Currently, this means
examining the installed tools for ShiningPanada. If the string matches an installed ShiningPanda Python tool
instance, the virtualenv within that block is generated from that ShiningPanda tool.
Otherwise, the text is treated "as-is". You can pass "python" to use the default Python installation of the node that the job runs on, or specify an executable path.