Using Click Commands in Python

Question

I have a Python program and I want to run it using command:

myprogram --readpower=some argument

Code

import click
import csv
import json
import sys
@click.group(invoke_without_command=True) 
@click.option('--version', is_flag=True, default=False, help='Prints out pyisg package version being used')
def cli(version):
 """
 This utility is used to convert a CSV file to JSON file
 """
 if version:
 print("This is version 1.0 software")
 sys.exit()
@cli.command()
@click.option('--readpower', type=str, default="",
 help='Path of the csv file which is to be read)')
def read_csv(readpower,readspike,readdip):
{
 if readpower: 
 print("reading power")
}
if __name__ == "__main__":
 cli()

The problem I am facing is that the command -

myprogram --readpower = some argument

does not work. I have to write the command as :

myprogram read_csv --readpower = some argument

• Code Name X: I have done the other things in "setup.py" so that i can use the name "myprogram" to run the script instead of using the name of my python script

Answer 1

Just get rid of the group since you don't want it. Use a command directly like:

Code:

import click
import sys
@click.command()
@click.option('--version', is_flag=True, default=False,
 help='Prints out pyisg package version being used')
@click.option('--readpower', type=str, default="",
 help='Path of the csv file which is to be read)')
def cli(version, readpower):
 """
 This utility is used to convert a CSV file to JSON file
 """
 if version:
 click.echo("This is version 1.0 software")
 sys.exit()
 if readpower != '':
 click.echo("reading power {}".format(readpower))

Test Code:

if __name__ == "__main__":
 cli('--readpower=3'.split())
 cli('--version'.split())

Answer 2

Click is actually doing what it is supposed to do. You created a group cli and added the single command read_csv. So click needs to know the command to know what to invoke because there could possibly be more and even nested commands. You could create a standalone click command read_csvand register it in your setup.py file like so:

# app.py
import click
# as a standalone command
@click.command()
@click.option('--readpower', type=str, default="")
def read_csv(readpower):
 click.echo("doing stuff...")
 if readpower:
 click.echo("reading {}...".format(readpower))
@click.group()
def cli():
 pass
@cli.command()
def do_stuff():
 click.echo("doing stuff...")
# as a subcommand in a group
@cli.command()
@click.option('--readpower', type=str, default="")
def read_csv(readpower):
 click.echo("doing something...")
 if readpower:
 click.echo("reading {}...".format(readpower))

And the setup:

# setup.py
from setuptools import setup
setup(
 name='app',
 version='0.1',
 py_modules=['app'],
 install_requires=['Click'],
 entry_points='''
 [console_scripts]
 read_csv=app:read_csv
 cli=app:cli
 ''',
)

So you can set multiple entry points to your application and mix multiple standalone commands with grouped (and even possibly nested) commands.