单击 python，如何避免重复多个子命令使用的参数代码
With python click, how can I avoid duplicating argument code used by multiple subcommands
我有一组子命令，它们都对 URL 列表进行操作，这些 URL 可以选择作为参数传递。我如何才能将此参数分配给组，而不是避免在每个子命令上重复参数定义？
当前代码：
from config import site_list
@click.group()
def cli():
pass
@cli.command()
@cli.argument('sites', nargs=-1)
def subcommand_one():
if sites:
site_list = sites
etc...
@cli.command()
@cli.argument('sites', nargs=-1)
def subcommand_two():
if sites:
site_list = sites
etc...
调用示例：
$ python sites.py subcommand_one www.example.com www.example2.com
我试过像这样将参数装饰器移动到组中：
@click.group()
@click.argument('sites', nargs=-1)
def cli(sites):
if sites:
site_list = sites
但是我会得到这个错误：
$ python sites.py subcommand_one
Usage: sites.py [OPTIONS] [SITES] COMMAND [ARGS]...
Try "sites.py --help" for help.
Error: Missing command.
click.argument 只是 returns 一个像其他装饰器一样的装饰器，因此您可以将它分配给某个变量：
import click
@click.group()
def cli():
pass
sites_argument = click.argument('sites', nargs=-1)
@cli.command()
@sites_argument
def subcommand_one(sites):
...
@cli.command()
@sites_argument
def subcommand_two(sites):
...
如果有一个特定的 nargs = -1 参数您只想装饰到组上，但适用于
根据需要执行所有命令，您可以使用一些额外的管道来执行此操作，例如：
这个答案的灵感来自 this 答案。
自定义Class
class GroupNArgsForCommands(click.Group):
"""Add special arguments on group"""
def __init__(self, *args, **kwargs):
super(GroupNArgsForCommands, self).__init__(*args, **kwargs)
cls = GroupNArgsForCommands.CommandArgument
# gather the special arguments for later
self._cmd_args = {
a.name: a for a in self.params if isinstance(a, cls)}
# strip out the special arguments from self
self.params = [a for a in self.params if not isinstance(a, cls)]
class CommandArgument(click.Argument):
"""class to allow us to find our special arguments"""
@staticmethod
def command_argument(*param_decls, **attrs):
"""turn argument type into type we can find later"""
assert 'cls' not in attrs, "Not designed for custom arguments"
attrs['cls'] = GroupNArgsForCommands.CommandArgument
def decorator(f):
click.argument(*param_decls, **attrs)(f)
return f
return decorator
def group(self, *args, **kwargs):
# any derived groups need to be the same type
kwargs['cls'] = GroupNArgsForCommands
def decorator(f):
grp = super(GroupNArgsForCommands, self).group(
*args, **kwargs)(f)
self.add_command(grp)
# any sub commands need to hook the same special args
grp._cmd_args = self._cmd_args
return grp
return decorator
def add_command(self, cmd, name=None):
# call original add_command
super(GroupNArgsForCommands, self).add_command(cmd, name)
# if this command's callback has desired parameters add them
import inspect
args = inspect.signature(cmd.callback)
if len(args.parameters):
for arg_name in reversed(list(args.parameters)):
if arg_name in self._cmd_args:
cmd.params[:] = [self._cmd_args[arg_name]] + cmd.params
使用自定义 Class:
要使用自定义 class，请将 cls 参数传递给 click.group() 装饰器，使用
@GroupNArgsForCommands.command_argument 特殊参数的装饰器，然后添加一个
根据需要与任何命令的特殊参数同名的参数。
@click.group(cls=GroupNArgsForCommands)
@GroupNArgsForCommands.command_argument('special', nargs=-1)
def a_group():
"""My project description"""
@a_group.command()
def a_command(special):
"""a command under the group"""
这是如何工作的？
之所以可行，是因为 click 是一个设计良好的 OO 框架。 @click.group() 装饰器通常
实例化一个 click.Group 对象，但允许使用 cls 参数覆盖此行为。
因此，在我们自己的 class 中继承 click.Group 并覆盖所需的方法是一件相对容易的事情。
在这种情况下，我们超越 click.Group.add_command()，以便在添加命令时我们可以检查
命令回调参数以查看它们是否与我们的任何特殊参数具有相同的名称。
如果它们匹配，则将参数添加到命令的参数中，就好像它已被直接修饰一样。
另外 GroupNArgsForCommands 实现了一个 command_argument() 方法。此方法用作
添加特殊参数而不是使用 click.argument()
时的装饰器
测试Class
import click
@click.group(cls=GroupNArgsForCommands)
@GroupNArgsForCommands.command_argument('sites', nargs=-1)
def cli():
click.echo("cli group")
@cli.command()
def command_one(sites):
click.echo("command_one: {}".format(sites))
@cli.group()
def subcommand():
click.echo("subcommand group")
@subcommand.command()
def one():
click.echo("subcommand_one")
@subcommand.command()
def two(sites):
click.echo("subcommand_two: {}".format(sites))
if __name__ == "__main__":
commands = (
'command_one site1 site2',
'command_one site1',
'command_one',
'subcommand',
'subcommand one site1 site2',
'subcommand one site1',
'subcommand one',
'subcommand two site1 site2',
'subcommand two site1',
'subcommand two',
'--help',
'command_one --help',
'subcommand --help',
'subcommand one --help',
'subcommand two --help',
'',
)
import sys, time
time.sleep(1)
print('Click Version: {}'.format(click.__version__))
print('Python Version: {}'.format(sys.version))
for command in commands:
try:
time.sleep(0.1)
print('-----------')
print('> ' + command)
time.sleep(0.1)
cli(command.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)]
-----------
> command_one site1 site2
cli group
command_one: ('site1', 'site2')
-----------
> command_one site1
cli group
command_one: ('site1',)
-----------
> command_one
cli group
command_one: ()
-----------
> subcommand
cli group
Usage: test.py subcommand [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
one
two
-----------
> subcommand one site1 site2
Usage: test.py subcommand one [OPTIONS]
Error: Got unexpected extra arguments (site1 site2)
cli group
subcommand group
-----------
> subcommand one site1
cli group
subcommand group
Usage: test.py subcommand one [OPTIONS]
Error: Got unexpected extra argument (site1)
-----------
> subcommand one
cli group
subcommand group
subcommand_one
-----------
> subcommand two site1 site2
cli group
subcommand group
subcommand_two: ('site1', 'site2')
-----------
> subcommand two site1
cli group
subcommand group
subcommand_two: ('site1',)
-----------
> subcommand two
cli group
subcommand group
subcommand_two: ()
-----------
> --help
Usage: test.py [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
command_one
subcommand
-----------
> command_one --help
cli group
Usage: test.py command_one [OPTIONS] [SITES]...
Options:
--help Show this message and exit.
-----------
> subcommand --help
cli group
Usage: test.py subcommand [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
one
two
-----------
> subcommand one --help
cli group
subcommand group
Usage: test.py subcommand one [OPTIONS]
Options:
--help Show this message and exit.
-----------
> subcommand two --help
cli group
subcommand group
Usage: test.py subcommand two [OPTIONS] [SITES]...
Options:
--help Show this message and exit.
-----------
>
Usage: test.py [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
command_one
subcommand
我认为 Click 使用 @click.pass_context.
支持实际的解决方案
当您想要定义一组共享公共参数和公共选项的命令时，您可以在组级别定义它们并将它们添加到上下文对象中，例如 described in the Click documentation。
@click.group(chain=True)
@click.argument("dataset_directory", type=click.Path(exists=True))
@click.option("-s", "--split-names", help="The splits to preprocess.", required=True,
default=["trainset", "devset", "testset"], show_default=True)
@click.pass_context
def cli(ctx, dataset_directory, split_names):
"""
Prepare the dataset for training
DATASET_DIRECTORY The absolute path to the data directory.
"""
ctx.ensure_object(dict)
ctx.obj["DIRECTORY"] = dataset_directory
ctx.obj["SPLITS"] = split_names
然后该组的各个命令可以通过上下文并使用上下文对象中的值，而不是定义它们自己的参数和选项。
@cli.command("create")
@click.pass_context
def create(ctx):
create_semantics_json_from_csv(ctx.obj["DIRECTORY"], ctx.obj["SPLITS"])
@cli.command("tokenize")
@click.pass_context
def tokenize(ctx):
preprocess_tokenize_semantics_json(ctx.obj["DIRECTORY"], ctx.obj["SPLITS"])
然后可以调用命令，例如：
my-cli-app /path/to/data create tokenize
我有一组子命令，它们都对 URL 列表进行操作，这些 URL 可以选择作为参数传递。我如何才能将此参数分配给组，而不是避免在每个子命令上重复参数定义？
当前代码：
from config import site_list
@click.group()
def cli():
pass
@cli.command()
@cli.argument('sites', nargs=-1)
def subcommand_one():
if sites:
site_list = sites
etc...
@cli.command()
@cli.argument('sites', nargs=-1)
def subcommand_two():
if sites:
site_list = sites
etc...
调用示例：
$ python sites.py subcommand_one www.example.com www.example2.com
我试过像这样将参数装饰器移动到组中：
@click.group()
@click.argument('sites', nargs=-1)
def cli(sites):
if sites:
site_list = sites
但是我会得到这个错误：
$ python sites.py subcommand_one
Usage: sites.py [OPTIONS] [SITES] COMMAND [ARGS]...
Try "sites.py --help" for help.
Error: Missing command.
click.argument 只是 returns 一个像其他装饰器一样的装饰器，因此您可以将它分配给某个变量：
import click
@click.group()
def cli():
pass
sites_argument = click.argument('sites', nargs=-1)
@cli.command()
@sites_argument
def subcommand_one(sites):
...
@cli.command()
@sites_argument
def subcommand_two(sites):
...
如果有一个特定的 nargs = -1 参数您只想装饰到组上，但适用于
根据需要执行所有命令，您可以使用一些额外的管道来执行此操作，例如：
这个答案的灵感来自 this 答案。
自定义Class
class GroupNArgsForCommands(click.Group):
"""Add special arguments on group"""
def __init__(self, *args, **kwargs):
super(GroupNArgsForCommands, self).__init__(*args, **kwargs)
cls = GroupNArgsForCommands.CommandArgument
# gather the special arguments for later
self._cmd_args = {
a.name: a for a in self.params if isinstance(a, cls)}
# strip out the special arguments from self
self.params = [a for a in self.params if not isinstance(a, cls)]
class CommandArgument(click.Argument):
"""class to allow us to find our special arguments"""
@staticmethod
def command_argument(*param_decls, **attrs):
"""turn argument type into type we can find later"""
assert 'cls' not in attrs, "Not designed for custom arguments"
attrs['cls'] = GroupNArgsForCommands.CommandArgument
def decorator(f):
click.argument(*param_decls, **attrs)(f)
return f
return decorator
def group(self, *args, **kwargs):
# any derived groups need to be the same type
kwargs['cls'] = GroupNArgsForCommands
def decorator(f):
grp = super(GroupNArgsForCommands, self).group(
*args, **kwargs)(f)
self.add_command(grp)
# any sub commands need to hook the same special args
grp._cmd_args = self._cmd_args
return grp
return decorator
def add_command(self, cmd, name=None):
# call original add_command
super(GroupNArgsForCommands, self).add_command(cmd, name)
# if this command's callback has desired parameters add them
import inspect
args = inspect.signature(cmd.callback)
if len(args.parameters):
for arg_name in reversed(list(args.parameters)):
if arg_name in self._cmd_args:
cmd.params[:] = [self._cmd_args[arg_name]] + cmd.params
使用自定义 Class:
要使用自定义 class，请将 cls 参数传递给 click.group() 装饰器，使用
@GroupNArgsForCommands.command_argument 特殊参数的装饰器，然后添加一个
根据需要与任何命令的特殊参数同名的参数。
@click.group(cls=GroupNArgsForCommands)
@GroupNArgsForCommands.command_argument('special', nargs=-1)
def a_group():
"""My project description"""
@a_group.command()
def a_command(special):
"""a command under the group"""
这是如何工作的？
之所以可行，是因为 click 是一个设计良好的 OO 框架。 @click.group() 装饰器通常
实例化一个 click.Group 对象，但允许使用 cls 参数覆盖此行为。
因此，在我们自己的 class 中继承 click.Group 并覆盖所需的方法是一件相对容易的事情。
在这种情况下，我们超越 click.Group.add_command()，以便在添加命令时我们可以检查
命令回调参数以查看它们是否与我们的任何特殊参数具有相同的名称。
如果它们匹配，则将参数添加到命令的参数中，就好像它已被直接修饰一样。
另外 GroupNArgsForCommands 实现了一个 command_argument() 方法。此方法用作
添加特殊参数而不是使用 click.argument()
测试Class
import click
@click.group(cls=GroupNArgsForCommands)
@GroupNArgsForCommands.command_argument('sites', nargs=-1)
def cli():
click.echo("cli group")
@cli.command()
def command_one(sites):
click.echo("command_one: {}".format(sites))
@cli.group()
def subcommand():
click.echo("subcommand group")
@subcommand.command()
def one():
click.echo("subcommand_one")
@subcommand.command()
def two(sites):
click.echo("subcommand_two: {}".format(sites))
if __name__ == "__main__":
commands = (
'command_one site1 site2',
'command_one site1',
'command_one',
'subcommand',
'subcommand one site1 site2',
'subcommand one site1',
'subcommand one',
'subcommand two site1 site2',
'subcommand two site1',
'subcommand two',
'--help',
'command_one --help',
'subcommand --help',
'subcommand one --help',
'subcommand two --help',
'',
)
import sys, time
time.sleep(1)
print('Click Version: {}'.format(click.__version__))
print('Python Version: {}'.format(sys.version))
for command in commands:
try:
time.sleep(0.1)
print('-----------')
print('> ' + command)
time.sleep(0.1)
cli(command.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)]
-----------
> command_one site1 site2
cli group
command_one: ('site1', 'site2')
-----------
> command_one site1
cli group
command_one: ('site1',)
-----------
> command_one
cli group
command_one: ()
-----------
> subcommand
cli group
Usage: test.py subcommand [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
one
two
-----------
> subcommand one site1 site2
Usage: test.py subcommand one [OPTIONS]
Error: Got unexpected extra arguments (site1 site2)
cli group
subcommand group
-----------
> subcommand one site1
cli group
subcommand group
Usage: test.py subcommand one [OPTIONS]
Error: Got unexpected extra argument (site1)
-----------
> subcommand one
cli group
subcommand group
subcommand_one
-----------
> subcommand two site1 site2
cli group
subcommand group
subcommand_two: ('site1', 'site2')
-----------
> subcommand two site1
cli group
subcommand group
subcommand_two: ('site1',)
-----------
> subcommand two
cli group
subcommand group
subcommand_two: ()
-----------
> --help
Usage: test.py [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
command_one
subcommand
-----------
> command_one --help
cli group
Usage: test.py command_one [OPTIONS] [SITES]...
Options:
--help Show this message and exit.
-----------
> subcommand --help
cli group
Usage: test.py subcommand [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
one
two
-----------
> subcommand one --help
cli group
subcommand group
Usage: test.py subcommand one [OPTIONS]
Options:
--help Show this message and exit.
-----------
> subcommand two --help
cli group
subcommand group
Usage: test.py subcommand two [OPTIONS] [SITES]...
Options:
--help Show this message and exit.
-----------
>
Usage: test.py [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
command_one
subcommand
我认为 Click 使用 @click.pass_context.
当您想要定义一组共享公共参数和公共选项的命令时，您可以在组级别定义它们并将它们添加到上下文对象中，例如 described in the Click documentation。
@click.group(chain=True)
@click.argument("dataset_directory", type=click.Path(exists=True))
@click.option("-s", "--split-names", help="The splits to preprocess.", required=True,
default=["trainset", "devset", "testset"], show_default=True)
@click.pass_context
def cli(ctx, dataset_directory, split_names):
"""
Prepare the dataset for training
DATASET_DIRECTORY The absolute path to the data directory.
"""
ctx.ensure_object(dict)
ctx.obj["DIRECTORY"] = dataset_directory
ctx.obj["SPLITS"] = split_names
然后该组的各个命令可以通过上下文并使用上下文对象中的值，而不是定义它们自己的参数和选项。
@cli.command("create")
@click.pass_context
def create(ctx):
create_semantics_json_from_csv(ctx.obj["DIRECTORY"], ctx.obj["SPLITS"])
@cli.command("tokenize")
@click.pass_context
def tokenize(ctx):
preprocess_tokenize_semantics_json(ctx.obj["DIRECTORY"], ctx.obj["SPLITS"])
然后可以调用命令，例如：
my-cli-app /path/to/data create tokenize