�ݺ�ߣ

PyCon 23: Smettiamola di scrivere script

Dizionario Italiano a cura di Enrico Olivetti

CLI Applications
What's wrong with scripts?
Why CLI Applications?
1. Argparse
2. Click
3. Docopt

print("This is important code")
1
2
for index, arg in enumerate(sys.argv):
3
print(f"[{index}]: {arg}")
4
What's Wrong with Scripts?
Easy to get started
Limited possibilities for structure
Hard to (unit) test
No dependency management
Deployment may require care
Custom user experience

print("Usage: foo <bar> --baz")
def main():
1
2
3
if __name__ == "__main__":
4
main()
5
Why CLI Applications?
Standardized user experience
More possibilities for structure
Possibilities for all kinds of testing
Dependency management
Packaging & distribution

import argparse
from . import __version__
def parse_arguments():
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('--version', action='version',
version=__version__)
parser.add_argument('filename')
args = parser.parse_args()
return args
def main():
args = parse_arguments()
...
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Argparse

import click
@click.command()
@click.version_option()
@click.argument('filename')
def main(filename):
click.echo(filename)
1
2
3
4
5
6
7
Click
import click
@click.command()
@click.argument('filename', type=click.Path(exists=True))
def main(filename):
click.echo(filename)
1
2
3
4
5
6
7
import click
@click.command()
@click.argument('infile', type=click.File())
def main(infile):
click.echo(infile.read())
1
2
3
4
5
6
7

"""Foobar
Usage:
foobar (-h | --help | --version)
foobar [-s | --silent] <file>
foobar [-v | --verbose] <file>
Positional arguments:
file target file path name
Optional arguments:
-h, --help show this help message and exit
-s, --silent don't show progress output
-v, --verbose explain progress verbosely
--version show program's version number and exit
"""
from docopt import docopt
from . import __version__
def parse_arguments():
args = docopt(__doc__, version=__version__)
return dict(
file=args['<file>'],
silent=args['-s'] or args['--silent'],
verbose=args['-v'] or args['--verbose'],
)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Docopt

$ copier gh:painless-software/python-cli-test-helpers pycon-italia-cli
🎤 engine
(Use arrow keys)
» Argparse
Click
Docopt
...
Demo
🐍 ✨
✨
https://python-cli-test-helpers.readthedocs.io

Thank you!
for your precious time
Painless Software
Less pain, more fun.
Most images taken from Wikipedia (CC-SA)
Alberto Sordi animated GIF stolen from giffetteria.it

�ݺ�ߣ

PyCon 23: Smettiamola di scrivere script

More Related Content

PyCon 23: Smettiamola di scrivere script