Introduction
Skal is a wrapper for the argparser library to make it easier to write applications that uses commands with subcommands, much like git and heroku does.
Skal can be used with different combinations of command sources; a subclass of SkalApp, any number of modules and any number of packages. Currently usage with classes and modules are supported.
The test cases are a good source of different ways to use Skal appart from what is described here.
Subclass as command source
A custom subclass of SkalApp is one way to get some commands added, and may be the shortest version.
In file myapp.py:
from skal import SkalApp, command
class MyApp(SkalApp):
@command
def hello(self):
print('hello')
@command
def yes(self):
print('yes')
if __name__ == '__main__':
MyApp().run()Running the program:
> python myapp.py hello
hello
> python myapp.py yes
yes
Modules as command source
There are two ways in which modules can be used to source commands; either as a flat hirearchy where every function in every module gets added or with a bit of hirearchy where each module becomes a command and its functions becomes subcommands. Using either is determined by how the module names are passed to the SkalApp constructor, and any combination is also valid. The only advice is to specify a overridden version and description string for the whole app, as Skal wouldn't otherwise know where to get that information from. When using only modules there is no need to override the SkalApp class.
First a module called do.py:
from skal import command
@command
def hello(self):
print('hello')
@command
def yes(self):
print('yes')Using do.py as plain commands in myapp.py:
from skal import SkalApp
if __name__ == '__main__':
SkalApp(command_modules = ['do']).run()
Running the program:
> python myapp.py hello
hello
> python myapp.py yes
yes
Using do.py as a subcommand in myapp.py:
from skal import SkalApp
if __name__ == '__main__':
SkalApp(subcommand_modules = ['do']).run()
Running the program:
> python myapp.py do hello
hello
> python myapp.py do yes
yes
Per Command Arguments
This shows the usage of custom arguments per command. This works for all supported command sources, not only classes.
from skal import SkalApp, command, default
class MyApp(SkalApp):
"""Help line for application"""
__args__ = {
'-a': {'help': 'Help for a', 'action': 'store_true'},
'-b': {'help': 'Help for b', 'action': 'store_true'}
}
@command({
('-d', '--delete'): {'help': 'Help for d', 'action': 'store_true'}
})
def hello(self):
"""Help line for hello"""
if self.args.a:
print('a')
if self.args.b:
print('b')
if self.args.delete:
print('deleting')
print('hello')
@command
def yes(self):
"""Help line for yes"""
if self.args.a:
print('a')
if self.args.b:
print('b')
print('yes')
if __name__ == '__main__':
app = MyApp()
sys.exit(app.run())Running it:
> python myapp.py -a hello --delete
a
deleting
hello
> python myapp.py -b yes
b
yes
License
Skal is licensed under Apache License 2.0
