scription 0.86.26

Description:

scription 0.86.26

scription
light-weight library to enhance command-line scripts; includes conversion of
parameters to specified data types, parameter checking, basic input/output with
users, support for suid [1], sending email, executing sub-programs, and having
sub-commands within a script
decorators


Script: sets global variables and/or parameters for Commands; the decorated
function will be called by Main/Run before any specified Command
Command: marks function as a subcommand for the script (e.g. add, delete,
list, etc.); if no subcommand is specified on the command-line, scription
will look for a Command with the same name as the script
Alias: registers other names for Commands (e.g. delete / remove / kill)


functions


Main: if the importing module’s __name__ is __main__, call Run() (this
allows for importing the script as a module)
Run: unconditionally attempts to run the Script function (if any) and the
Command found on the command-line

Main() or Run() should be the last thing in the script

classes


Spec: can be used when defining the command-line parameters (can also just
use tuples)


helper functions/classes


abort: quits immediately by raising SystemExit
Execute: class for executing other programs; uses subprocess.Popen by
default, but if pty=True is specified then pty.fork will be used
(handy for programs that only accept input from a pty)
get_response: function for displaying text and getting feedback
help: quits immediately, but adds a reference to –help in the quit message
log_exception: logs an exception with logging.logger
mail: rudimentary mail sender
OrmFile: lightweight orm – supports str, int, float, date, time,
datetime, bool, and path (which defaults to str); custom data types can
also be specified
print: wrapper around print that adds a ‘verbose_level’ keyword (default: 1);
default verbosity is 0 (so print does nothing), but can be increased using
-v, -vv, –verbose, or –verbose=2 (in Python 2 the script must use
‘from __future__ import print_function’ to use scription’s print)
user_ids: context manager useful for suid scripts – all actions taken
within the context are run as the user/group specified


features


extra parameters defined by Script are global, and can be accessed from any
function or Command
‘module’ is a namespace inserted into the script
‘script_command’ is the Command selected from the command line (useful when
one needs to call the subcommand directly from a main() function)
‘script_command_name’ is the name of the script_command
‘script_verbosity’ is the level of verboseness selected (defaults to 0)
‘script_name’ is the name of the script
builtin options are: –help, –verbose (-v or -vv), –version, –all-versions
–version attempts to display the version of the main package in use
–all-versions attempts to display the versions of any imported packages
command-line is decoded to unicode under Python 2 (Python 3 does this for us)


[1] I use the suid-python program, available at http://selliott.org/python/suid-python.c