Question

在正常情况下，我的应用程序会将一组配置值加载到上下文中，并将这些配置值通过pass_context传递给子命令。在仅有的一种情况下，这是行不通的-第一次运行该应用程序且尚未设置配置。

我的目标是允许用户运行一个子命令并生成适当的配置，以便CLI在其余时间正常工作。

我的cli.py代码：

import sys
import click
from ruamel.yaml import YAML
from pathlib import Path

from commands.config_cmds import configcmd

MYAPP = "AwesomeCLI"

@click.group()
@click.version_option()
@click.pass_context
def cli(ctx):
    """command line application"""
    ctx.ensure_object(dict)
    ctx.obj['APPLICATION_NAME'] = MYAPP

    config_file = Path(click.get_app_dir(ctx.obj[MYAPP])) / "config.yml"
    yaml = YAML(typ="safe")
    try:
        config_yml = yaml.load(config_file)
    except FileNotFoundError:
        click.secho("Run command: awesome-cli configcmd first-run", fg='red')
        raise click.FileError(config_file.name, "Missing configuration file.")

    ctx.obj['CONFIG'] = yaml.dump(config_yml)


cli.add_command(configcmd)

我的configcmd代码：

@click.group()
def configcmd():
    """Manage configuration of this tool
    \f
    The configuration file is saved in $HOME/.config/awesome-cli
    """

@config.command()
@click.pass_context
def first_run(ctx):
    """
    Set up CLI configuration. 
    """
    api_key = click.prompt("Your API Key")
    # More stuff here about saving this file...

如果我运行python awesome-cli configcmd，则会收到以下错误（按预期）：

Run command: awesome-cli configcmd first-run
Error: Could not open file config.yml: Missing configuration file.

但是，如果我运行该命令python awesome-cli configcmd first-run，则会收到相同的错误，这不是我的目标。显然我应该在此代码中遇到该错误，但这是因为我不知道如何基于被调用的命令/子命令添加异常。

我需要在cli的{{1}}函数中添加什么，以便当（且仅）当用户正在运行{{1}时，才尝试加载配置文件}？任何其他命令/子命令都需要该配置文件存在，所以我希望保留对这些配置文件的检查。

Answer 1

要在执行基于所调用的特定子命令的子命令之前调用一些特定的代码，可以像下面这样查看ctx.invoked_subcommand：

if ctx.invoked_subcommand != 'configcmd':

在您的示例中，您将需要检查各个级别的ctx.invoked_subcommand，例如：

测试代码：

import sys
import click
from ruamel.yaml import YAML
from pathlib import Path

MYAPP = "AwesomeCLI"

@click.group()
@click.pass_context
def cli(ctx):
    """command line application"""
    ctx.ensure_object(dict)
    ctx.obj['APPLICATION_NAME'] = MYAPP
    ctx.obj['CONFIG_FILEPATH'] = Path(click.get_app_dir(MYAPP), "config.yml")
    if ctx.invoked_subcommand != 'configcmd':
        load_config(ctx)

@cli.group()
@click.pass_context
def configcmd(ctx):
    """Configuration management for this CLI"""
    click.echo("In config")
    if ctx.invoked_subcommand != 'first-run':
        load_config(ctx)

def load_config(ctx):
    yaml = YAML(typ="safe")
    try:
        config_yml = yaml.load(ctx.obj['CONFIG_FILEPATH'])
    except FileNotFoundError:
        click.secho("Run command: awesome-cli configcmd first-run",
                    fg='red')
        raise click.FileError(str(ctx.obj['CONFIG_FILEPATH']),
                              "Missing configuration file.")

    ctx.obj['CONFIG'] = yaml.load(config_yml)


@configcmd.command('first-run')
@click.pass_context
def first_run(ctx):
    """Set up CLI configuration."""
    click.echo("In first-run")

@configcmd.command('test-cmd')
@click.pass_context
def test_cmd(ctx):
    """ This command will not be reachable without config file"""
    click.echo("In first-run")


if __name__ == "__main__":
    commands = (
        'configcmd first-run',
        'configcmd test-cmd',
        'configcmd --help',
        '--help',
        '',
    )

    import sys, time

    time.sleep(1)
    print('Click Version: {}'.format(click.__version__))
    print('Python Version: {}'.format(sys.version))
    for cmd in commands:
        try:
            time.sleep(0.1)
            print('-----------')
            print('> ' + cmd)
            time.sleep(0.1)
            cli(cmd.split())

        except BaseException as exc:
            if str(exc) != '0' and \
                    not isinstance(exc, (click.ClickException, SystemExit)):
                raise

结果：

Click Version: 6.7
Python Version: 3.6.3 (v3.6.3:2c5fed8, Oct  3 2017, 18:11:49) [MSC v.1900 64 bit (AMD64)]
-----------
> configcmd first-run
In config
In first-run
-----------
> configcmd test-cmd
In config
Run command: awesome-cli configcmd first-run
Error: Could not open file C:\Users\stephen\AppData\Roaming\AwesomeCLI\config.yml: Missing configuration file.
-----------
> configcmd --help
Usage: test.py configcmd [OPTIONS] COMMAND [ARGS]...

  Configuration management for this CLI

Options:
  --help  Show this message and exit.

Commands:
  first-run  Set up CLI configuration.
  test-cmd   This command will not be reachable without...
-----------
> --help
Usage: test.py [OPTIONS] COMMAND [ARGS]...

  command line application

Options:
  --help  Show this message and exit.

Commands:
  configcmd  Configuration management for this CLI
-----------
> 
Usage: test.py [OPTIONS] COMMAND [ARGS]...

  command line application

Options:
  --help  Show this message and exit.

Commands:
  configcmd  Configuration management for this CLI

如果调用了特定的子命令，则执行不同的父命令操作？

1 个答案:

测试代码：

结果：