output.
+.. exception:: SubprocessError
+
+ Base class for all other exceptions from this module.
+
+ .. versionadded:: 3.3
+
+
+.. exception:: TimeoutExpired
+
+ Subclass of :exc:`SubprocessError`, raised when a timeout expires
+ while waiting for a child process.
+
+ .. attribute:: cmd
+
+ Command that was used to spawn the child process.
+
+ .. attribute:: timeout
+
+ Timeout in seconds.
+
+ .. attribute:: output
+
+ Output of the child process if this exception is raised by
+ :func:`check_output`. Otherwise, ``None``.
+
+ .. versionadded:: 3.3
+
+
+.. exception:: CalledProcessError
+
+ Subclass of :exc:`SubprocessError`, raised when a process run by
+ :func:`check_call` or :func:`check_output` returns a non-zero exit status.
+
+ .. attribute:: returncode
+
+ Exit status of the child process.
+
+ .. attribute:: cmd
+
+ Command that was used to spawn the child process.
+
+ .. attribute:: output
+
+ Output of the child process if this exception is raised by
+ :func:`check_output`. Otherwise, ``None``.
+
+
+
.. _frequently-used-arguments:
Frequently Used Arguments