command - Wrap complex commands in Python objects

Tools to wrap a Python API around interactive and non-interactive programs.

The command.Command and interpreter.Interpreter classes are meant to be derived from in order to handle batch and interactive commands respectively. They can be provided with option.Config instances which describe the options available to the programs being wrapped. The option.Parser class can then be used to validate option sets and construct the corresponding command lines. See the svn.svn module for a concrete example.

command - Drive batch commands with function calls

Non interactive command driver.

class Command(cmd, debug=False)

Represents the command to be executed. Typically you would derive from this class and provide a different method for each alternative way of invoking the program. If the program you want to execute has many sub-commands you might provide a different method for each sub-command. You can use the option.Config class to declare the options supported by your command and then use the config.Parser class to validate your methods’ arguments and generate the resulting command line. A debug mode is available in which commands are echoed rather than run. This can be enabled globally or separately for each invocation.

run(parser, debug=False)

Executes the command. Takes as arguments a command line parser (see the option module) and a boolean indicating whether debug mode should be used for this execution.

exception Error(cmd, returncode, err)

Raised when command execution fails.

error - The command package exception hierarchy

Exception classes for the nxpy.command package.

exception BadLogFormat

Raised if the requested formatting option is unknown

exception Error

Package exceptions’ base class

exception ExpectError

Raised on invalid input from stdout or stderr

exception TimeoutError

Raised when expect didn’t satisfy a timing constraint

exception TimerError

Raised on misuse of the Timer class

interpreter - Wrap interactive programs in Python classes

Interactive program driver.

exception BadCommand(cmd, err)

Raised on a command execution failure

class BaseInterpreter(popen)

Controls the execution of an interactive program in a sub-process. Provides means to send input to the controlled process and to check different conditions on its output and error streams.

class Interpreter(cmd)

The actual Interpreter class. Optionally accepts an alternative ‘subprocess’ implementation.

class Timer(timeout, retries, interval=0.1, quantum=0.01)

A collaborative timer class

option - Describe complex command lines

Function argument to command line option conversion. Provides means to describe commands with complicated syntaxes, which often combine sub-commands, options and arguments. Typical examples include subversion and ftp.

class Config(prefix='--', separator=' ', bool_opts=(), value_opts=(), iterable_opts=(), format_opts={}, mapped_opts={}, opposite_opts={})

Command option definitions. Provides a single definition point for all the options supported by a command.

exception InvalidOptionError

Raised when an option is not supported.

class Parser(config, command, arguments, options, **defaults)

Constructs a complex command line from the provided ‘command’ and its ‘options’ and ‘arguments’. Uses a Config instance, ‘config’, to provide means to check conditions on the supplied options.