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Next Steps

Once your current application is using cmd2, you can start to expand the functionality by leveraging other cmd2 features. The three ideas here will get you started. Browse the rest of the Features to see what else cmd2 can help you do.

Argument Parsing

For all but the simplest of commands, it's probably easier to use argparse to parse user input than to do it manually yourself for each command. cmd2 provides a @with_argparser() decorator which associates an ArgumentParser object with one of your commands. Using this method will:

  1. Pass your command a Namespace containing the arguments instead of a string of text
  2. Properly handle quoted string input from your users
  3. Create a help message for you based on the ArgumentParser
  4. Give you a big head start adding Tab Completion to your application
  5. Make it much easier to implement subcommands (i.e. git has a bunch of subcommands such as git pull, git diff, etc)

There's a lot more about Argument Processing if you want to dig in further.

Help

If you have a lot of commands in your application, cmd2 can categorize those commands using a one line decorator @with_category(). When a user types help the available commands will be organized by the category you specified.

If you were already using argparse or decided to switch to it, you can easily standardize all of your help messages to be generated by your argument parsers and displayed by cmd2. No more help messages that don't match what the code actually does.

Generating Output

If your program generates output by printing directly to sys.stdout, you should consider switching to cmd2.Cmd.poutput, cmd2.Cmd.perror, and cmd2.Cmd.pfeedback. These methods work with several of the built in Settings to allow the user to view or suppress feedback (i.e. progress or status output). They also properly handle ANSI colored output according to user preference. cmd2's dependency on rich makes it easy to add color and style to your output. See the Colored Output section for more details. These and other related topics are covered in Generating Output.