type -cli:如何使用自定义数据类型

Question

点击已点击。ParamType，用于定义自定义参数类型，但它不适用于typer(下面的示例片段)

我想使用我自己的日期时间格式，例如:today %H:%M， %M:%H(自动使用日期作为今天)。type已经允许设置，自定义日期时间格式，但它不包括我的用例。

这是点击文档的例子，我尝试使用类型.

class BasedIntParamType(click.ParamType):
name = "integer"
def convert(self, value, param, ctx):
if isinstance(value, int):
return value
try:
if value[:2].lower() == "0x":
return int(value[2:], 16)
elif value[:1] == "0":
return int(value, 8)
return int(value, 10)
except ValueError:
self.fail(f"{value!r} is not a valid integer", param, ctx)
BASED_INT = BasedIntParamType()
def main(based_int: BASED_INT):
print(based_int)

if __name__=="__main__":
typer.run(main)

给出如下错误:

Traceback (most recent call last):
File "/home/yashrathi/test.py", line 26, in <module>
typer.run(main)
File "/home/yashrathi/.local/lib/python3.9/site-packages/typer/main.py", line 859, in run
app()
File "/home/yashrathi/.local/lib/python3.9/site-packages/typer/main.py", line 214, in __call__
return get_command(self)(*args, **kwargs)
File "/home/yashrathi/.local/lib/python3.9/site-packages/typer/main.py", line 239, in get_command
click_command = get_command_from_info(typer_instance.registered_commands[0])
File "/home/yashrathi/.local/lib/python3.9/site-packages/typer/main.py", line 423, in get_command_from_info
) = get_params_convertors_ctx_param_name_from_function(command_info.callback)
File "/home/yashrathi/.local/lib/python3.9/site-packages/typer/main.py", line 404, in get_params_convertors_ctx_param_name_from_function
click_param, convertor = get_click_param(param)
File "/home/yashrathi/.local/lib/python3.9/site-packages/typer/main.py", line 656, in get_click_param
parameter_type = get_click_type(
File "/home/yashrathi/.local/lib/python3.9/site-packages/typer/main.py", line 587, in get_click_type
raise RuntimeError(f"Type not yet supported: {annotation}")  # pragma no cover
RuntimeError: Type not yet supported: <__main__.BasedIntParamType object at 0x7f7295822fd0>

typer.main.get_click_type，似乎与自定义点击类型不兼容。但是click知道如何处理click.ParamType, typer不需要将其转换为click类型。

实现我自己的日期时间格式的最好方法是什么?

• 是否可以创建一个继承datetime的新类，并覆盖strptime以适合我的用例?
• 这可以由类型本身实现吗?因为点击
很容易做到这一点

谢谢你

Answer 1

我不熟悉typer，但是，这里是如何使用click来接近它。

实现日期时间格式的一种方法是从click.ParamType扩展并自己完成所有硬解析。

或者，如果你只是想对click.DateTime的工作方式做一些小的调整，你也可以直接从click.DateTime扩展。
这样你就可以让click.DateTime做大部分的繁重工作。

为了简化您的情况，假设我们希望允许用户指定:

$ cli --newdate today    # which converts today to a click.DateTime
2021-12-30               # Note: below I also show how to return "today" 

此外，我们希望保留click.DateTime的旧行为，这样它也可以工作:

$ cli --newdate 2042-12-29
2042-12-29

那么我们可以这样实现:

import datetime
from typing import Optional, Sequence, Any
import click
class EnhancedDate(click.DateTime):
name = "enhanceddate"
def __init__(self, formats: Optional[Sequence[str]] = None):
super().__init__(formats)
self.formats += ["today"]  # add your formats here
def convert(self, value: Any, param: Optional["Parameter"], ctx: Optional["Context"]) -> Any:
# And in the convert, we'll handle our own formats first
if value is None or value == "today":
return datetime.date.today()
# Alternatively, if you return "today" here 
# you also get the "today" string in your commands
# when you use type=EnhancedDate()

# we'll let click handle all the other stuff
return super().convert(value, param, ctx)
@click.command()
@click.option("--newdate", type=EnhancedDate())
def cli(newdate):
click.echo(newdate)

cli()

这种方法的好处是，你得到了点击文档:

python3 cli.py --help
Usage: cli.py [OPTIONS]
Options:
--newdate [%Y-%m-%d|%Y-%m-%dT%H:%M:%S|%Y-%m-%d %H:%M:%S|today]
--help                          Show this message and exit.
# Notice how `today` is added automatically over here:       ^

我希望这对你有帮助。