8.18.1 Popen3 Objects

Instances of the Popen3 class have the following methods:

poll ()

Returns -1 if child process hasn't completed yet, or its return code otherwise.

wait ()

Waits for and returns the return code of the child process.

The following attributes of Popen3 objects are also available:

fromchild

A file object that provides output from the child process.

tochild

A file object that provides input to the child process.

childerr

Where the standard error from the child process goes is capturestderr was true for the constructor, or None.

pid

The process ID of the child process.