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author | Elena ``of Valhalla'' Grandi <valhalla@trueelena.org> | 2022-03-12 20:20:15 +0100 |
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committer | Elena ``of Valhalla'' Grandi <valhalla@trueelena.org> | 2022-03-12 20:20:15 +0100 |
commit | 049f21cfe779dbcd795d04917dff4ec3034a1546 (patch) | |
tree | d2a6de4168709cb01324a37619d4c350128ec6ee /docs | |
parent | 11da28ef036aeb872f1e5c509b43ae6b9bb64da2 (diff) |
Beginning of a tutorial in the docs
Diffstat (limited to 'docs')
-rwxr-xr-x | docs/source/examples/greeter.py | 40 | ||||
-rw-r--r-- | docs/source/index.rst | 1 | ||||
-rw-r--r-- | docs/source/tutorial.rst | 98 |
3 files changed, 139 insertions, 0 deletions
diff --git a/docs/source/examples/greeter.py b/docs/source/examples/greeter.py new file mode 100755 index 0000000..5a978f4 --- /dev/null +++ b/docs/source/examples/greeter.py @@ -0,0 +1,40 @@ +#!/usr/bin/env python3 +import hazwaz + + +class World(hazwaz.Command): + """ + Greet the whole world. + """ + + def main(self): + print("Hello world!") + + +class Individual(hazwaz.Command): + """ + Greet an individual. + """ + + def add_arguments(self, parser): + parser.add_argument( + "gretee", + help="The person to be greeted", + ) + + def main(self): + print("Hello {}".format(self.args.gretee)) + + +class Greet(hazwaz.MainCommand): + """ + Greet people in different ways. + """ + commands = ( + World(), + Individual(), + ) + + +if __name__ == "__main__": + Greet().run() diff --git a/docs/source/index.rst b/docs/source/index.rst index 2b5c1f0..3440917 100644 --- a/docs/source/index.rst +++ b/docs/source/index.rst @@ -15,6 +15,7 @@ Contents :maxdepth: 2 :caption: Contents: + tutorial reference/modules Indices and tables diff --git a/docs/source/tutorial.rst b/docs/source/tutorial.rst new file mode 100644 index 0000000..eb077fd --- /dev/null +++ b/docs/source/tutorial.rst @@ -0,0 +1,98 @@ +********** + Tutorial +********** + +In this tutorial, we'll write a command that greets people in different +ways. + +We start with the scaffolding (shebang, imports, …) and with a class +that subclasses :py:class:`MainCommand <hazwaz.command.MainCommand>`, is +instantiated and its method :py:meth:`run +<hazwaz.command.MainCommand.run>` is called:: + + + #!/usr/bin/env python3 + import hazwaz + + + class Greet(hazwaz.MainCommand): + """ + Greet people in different ways. + """ + + + if __name__ == "__main__": + Greet().run() + +Save this in a file called greeter.py and run it, and it will print an +help message where you can already see a couple of options, +``--verbose`` and ``debug``, as well as the first line of the docstring +used as the usage. + +Now we add our first subcommand: we write a new class, subclassing +:py:class:`Command <hazwaz.command.Command>` and writing some code in +its :py:meth:`main <hazwaz.command.Command.main>` method:: + + class World(hazwaz.Command): + """ + Greet the whole world. + """ + + def main(self): + print("Hello world!") + +And we add an instance to the tuple of subcommands in our MainCommand:: + + class Greet(hazwaz.MainCommand): + """ + Greet people in different ways. + """ + commands = ( + World(), + ) + +now if we run the program as ``./greeter.py`` we see that there is a +possible choice for a positional argument, ``world``, and if we run +``./greeter.py world`` we get, as expected, a greeting ``Hello world!``. + +With ``./greeter.py world --help`` we can see the help message for this +subcommand, and notice that the first line in the docstring has again +been used as the usage notes. + +Of course, a subcommand can also have options: we write a second +subclass of :py:class:`Command <hazwaz.command.Command>` and this time +we add some argparser option in the :py:meth:`add_arguments +<hazwaz.command.Command.add_arguments>` method:: + + class Individual(hazwaz.Command): + """ + Greet an individual. + """ + + def add_arguments(self, parser): + parser.add_argument( + "gretee", + help="The person to be greeted", + ) + + def main(self): + print("Hello {}".format(self.args.gretee)) + +And again we add it to the tuple of subcommands:: + + class Greet(hazwaz.MainCommand): + """ + Greet people in different ways. + """ + commands = ( + World(), + Individual(), + ) + +You can then run the program as ``./greeter.py individual Bob`` to see +the new greeting. + +:py:meth:`add_arguments <hazwaz.command.Command.add_arguments>` requires +an :py:class:`argparse.ArgumentParser` as its second parameter, and +uses it to add arbitrary arguments, giving access to all argparse +features. |