معرفی شرکت ها
argtyped-0.4.0
تبلیغات ما
مشتریان به طور فزاینده ای آنلاین هستند. تبلیغات می تواند به آنها کمک کند تا کسب و کار شما را پیدا کنند.
مشاهده بیشتر
تبلیغات ما
مشتریان به طور فزاینده ای آنلاین هستند. تبلیغات می تواند به آنها کمک کند تا کسب و کار شما را پیدا کنند.
مشاهده بیشتر
تبلیغات ما
مشتریان به طور فزاینده ای آنلاین هستند. تبلیغات می تواند به آنها کمک کند تا کسب و کار شما را پیدا کنند.
مشاهده بیشتر
تبلیغات ما
مشتریان به طور فزاینده ای آنلاین هستند. تبلیغات می تواند به آنها کمک کند تا کسب و کار شما را پیدا کنند.
مشاهده بیشتر
تبلیغات ما
مشتریان به طور فزاینده ای آنلاین هستند. تبلیغات می تواند به آنها کمک کند تا کسب و کار شما را پیدا کنند.
مشاهده بیشترتوضیحات
Command line arguments, with types
| ویژگی | مقدار |
|---|---|
| سیستم عامل | - |
| نام فایل | argtyped-0.4.0 |
| نام | argtyped |
| نسخه کتابخانه | 0.4.0 |
| نگهدارنده | [] |
| ایمیل نگهدارنده | [] |
| نویسنده | Zecong Hu |
| ایمیل نویسنده | huzecong@gmail.com |
| آدرس صفحه اصلی | https://github.com/huzecong/argtyped |
| آدرس اینترنتی | https://pypi.org/project/argtyped/ |
| مجوز | MIT License |
# `argtyped`: Command Line Argument Parser, with Types
[](https://github.com/huzecong/argtyped/actions?query=workflow%3ABuild+branch%3Amaster)
[](https://codecov.io/gh/huzecong/argtyped)
[](https://pypi.org/project/argtyped/)
[](https://github.com/huzecong/argtyped/blob/master/LICENSE)
`argtyped` is an command line argument parser with that relies on type annotations. It is built on
[`argparse`](https://docs.python.org/3/library/argparse.html), the command line argument parser library built into
Python. Compared with `argparse`, this library gives you:
- More concise and intuitive syntax, less boilerplate code.
- Type checking and IDE auto-completion for command line arguments.
- A drop-in replacement for `argparse` in most cases.
Since v0.4.0, `argtyped` also supports parsing arguments defined with an [attrs](https://attrs.org/)-class. See
[Attrs Support](#attrs-support-new) for more details.
## Installation
Install stable release from [PyPI](https://pypi.org/project/argtyped/):
```bash
pip install argtyped
```
Or, install the latest commit from GitHub:
```bash
pip install git+https://github.com/huzecong/argtyped.git
```
## Usage
With `argtyped`, you can define command line arguments in a syntax similar to
[`typing.NamedTuple`](https://docs.python.org/3/library/typing.html#typing.NamedTuple). The syntax is intuitive and can
be illustrated with an example:
```python
from typing import Optional
from typing_extensions import Literal # or directly import from `typing` in Python 3.8+
from argtyped import Arguments, Switch
from argtyped import Enum, auto
class LoggingLevels(Enum):
Debug = auto()
Info = auto()
Warning = auto()
Error = auto()
Critical = auto()
class MyArguments(Arguments):
model_name: str # required argument of `str` type
hidden_size: int = 512 # `int` argument with default value of 512
activation: Literal["relu", "tanh", "sigmoid"] = "relu" # argument with limited choices
logging_level: LoggingLevels = LoggingLevels.Info # using `Enum` class as choices
use_dropout: Switch = True # switch argument, enable with "--use-dropout" and disable with "--no-use-dropout"
dropout_prob: Optional[float] = 0.5 # optional argument, "--dropout-prob=none" parses into `None`
args = MyArguments()
```
This is equivalent to the following code with Python built-in `argparse`:
```python
import argparse
from enum import Enum
class LoggingLevels(Enum):
Debug = "debug"
Info = "info"
Warning = "warning"
Error = "error"
Critical = "critical"
parser = argparse.ArgumentParser()
parser.add_argument("--model-name", type=str, required=True)
parser.add_argument("--hidden-size", type=int, default=512)
parser.add_argument("--activation", choices=["relu", "tanh", "sigmoid"], default="relu")
parser.add_argument("--logging-level", choices=list(LoggingLevels), type=LoggingLevels, default="info")
parser.add_argument("--use-dropout", action="store_true", dest="use_dropout", default=True)
parser.add_argument("--no-use-dropout", action="store_false", dest="use_dropout")
parser.add_argument("--dropout-prob", type=lambda s: None if s.lower() == 'none' else float(s), default=0.5)
args = parser.parse_args()
```
Save the code into a file named `main.py`. Suppose the following arguments are provided:
```bash
python main.py \
--model-name LSTM \
--activation sigmoid \
--logging-level debug \
--no-use-dropout \
--dropout-prob none
```
Then the parsed arguments will be equivalent to the following structure returned by `argparse`:
```python
argparse.Namespace(
model_name="LSTM", hidden_size=512, activation="sigmoid", logging_level="debug",
use_dropout=False, dropout_prob=None)
```
Arguments can also be pretty-printed:
```
>>> print(args)
<class '__main__.MyArguments'>
╔═════════════════╤══════════════════════════════════╗
║ Arguments │ Values ║
╠═════════════════╪══════════════════════════════════╣
║ model_name │ 'LSTM' ║
║ hidden_size │ 512 ║
║ activation │ 'sigmoid' ║
║ logging_level │ <MyLoggingLevels.Debug: 'debug'> ║
║ use_dropout │ False ║
║ dropout_prob │ None ║
║ label_smoothing │ 0.1 ║
║ some_true_arg │ True ║
║ some_false_arg │ False ║
╚═════════════════╧══════════════════════════════════╝
```
It is recommended though to use the `args.to_string()` method, which gives you control of the table width.
## Attrs Support (New)
The way we define the arguments is very similar to defining a [dataclass](https://docs.python.org/3/library/dataclasses.html)
or an [attrs](https://attrs.org)-class, so it seems natural to just write an attrs-class, and add parsing support to it.
To use `argtyped` with `attrs`, simply define an attrs-class as usual, and have it subclass `AttrsArguments`. Here's
the same example above, but implemented with attrs-classes, and with some bells and whistles:
```python
import attr # note: new style `attrs` syntax is also supported
from argtyped import AttrsArguments
def _convert_logging_level(s: str) -> LoggingLevels:
# Custom conversion function that takes the raw string value from the command line.
return LoggingLevels[s.lower()]
@attr.s(auto_attribs=True)
class MyArguments(AttrsArguments):
model_name: str = attr.ib(metadata={"positional": True}) # positional argument
# Or: `model_name: str = argtyped.positional_arg()`.
layer_sizes: List[int] = attr.ib(metadata={"nargs": "+"}) # other metadata are treated as `argparse` options
activation: Literal["relu", "tanh", "sigmoid"] = "relu"
logging_level: LoggingLevels = attr.ib(default=LoggingLevels.Info, converter=_convert_logging_level)
use_dropout: Switch = True
dropout_prob: Optional[float] = 0.5
_activation_fn: Callable[[float], float] = attr.ib(init=False) # `init=False` attributes are not parsed
@dropout_prob.validator # validators still work as you would expect
def _dropout_prob_validator(self, attribute, value):
if not 0.0 <= value <= 1.0:
raise ValueError(f"Invalid probability {value}")
@_activation_fn.default
def _activation_fn(self):
return _ACTIVATION_FNS[self.activation]
```
A few things to note here:
- You can define positional arguments by adding `"positional": True` as metadata. If this feels unnatural, you could
also use `argtyped.positional_arg()`, which takes the same arguments as `attr.ib`.
- You can pass additional options to `ArgumentParser.add_argument` by listing them as metadata as well. Note that
these options take precedence over `argtyped`'s computed arguments, for example, sequence arguments (`List[T]`) by
default uses `nargs="*"`, but you could override it with metadata.
- Attributes with custom converters will not be parsed; its converter will be called with the raw string value from
command line. If the attribute also has a default value, you should make sure that your converter works with both
strings and the default value.
- `init=False` attributes are not treated as arguments, but they can be useful for storing computed values based on
arguments.
- The default value logic is the same as normal attrs classes, and thus could be different from non-attrs `argtyped`
classes. For example, optional arguments are not considered to have an implicit default of `None`, and no type
validation is performed on default values.
Here are the (current) differences between an attrs-based arguments class (`AttrsArguments`) versus the normal arguments
class (`Arguments`):
- `AttrsArguments` supports positional arguments and custom options via metadata.
- `AttrsArguments` handles default values with attrs, so there's no validation of default value types. This also
means that nullable arguments must have an explicit default value of `None`, otherwise it becomes a required
argument.
- `AttrsArguments` does not support `underscore=True`.
- `AttrsArguments` does not have `to_dict`, `to_string` methods.
- `AttrsArguments` needs to be called with the factory `parse_args` method to parse, while `Arguments` parses command
line arguments on construction.
## Reference
### The `argtyped.Arguments` Class
The `argtyped.Arguments` class is main class of the package, from which you should derive your custom class that holds
arguments. Each argument takes the form of a class attribute, with its type annotation and an optional default value.
When an instance of your custom class is initialized, the command line arguments are parsed from `sys.argv` into values
with your annotated types. You can also provide the list of strings to parse by passing them as the parameter.
The parsed arguments are stored in an object of your custom type. This gives you arguments that can be auto-completed
by the IDE, and type-checked by a static type checker like [mypy](http://mypy-lang.org/).
The following example illustrates the keypoints:
```python
class MyArgs(argtyped.Arguments):
# name: type [= default_val]
value: int = 0
args = MyArgs() # equivalent to `parser.parse_args()`
args = MyArgs(["--value", "123"]) # equivalent to `parser.parse_args(["--value", "123"])
assert isinstance(args, MyArgs)
```
#### `Arguments.to_dict(self)`
Convert the set of arguments to a dictionary (`OrderedDict`).
#### `Arguments.to_string(self, width: Optional[int] = None, max_width: Optional[int] = None)`
Represent the arguments as a table.
- `width`: Width of the printed table. Defaults to `None`, which fits the table to its contents. An exception is raised
when the table cannot be drawn with the given width.
- `max_width`: Maximum width of the printed table. Defaults to `None`, meaning no limits. Must be `None` if `width` is
not `None`.
#### `argtyped.argument_specs`
Return a dictionary mapping argument names to their specifications, represented as the `argtyped.ArgumentSpec` type.
This is useful for programmatically accessing the list of arguments.
### Argument Types
To summarize, whatever works for `argparse` works here. The following types are supported:
- **Built-in types** such as `int`, `float`, `str`.
- **Boolean type** `bool`. Accepted values (case-insensitive) for `True` are: `y`, `yes`, `true`, `ok`; accepted values
for `False` are: `n`, `no`, `false`.
- **Choice types** `Literal[...]`. A choice argument is essentially an `str` argument with limited
choice of values. The ellipses can be filled with a tuple of `str`s, or an expression that evaluates to a list of
`str`s:
```python
from argtyped import Arguments
from typing_extensions import Literal
class MyArgs(Arguments):
foo: Literal["debug", "info", "warning", "error"] # 4 choices
# argv: ["--foo=debug"] => foo="debug"
```
This is equivalent to the `choices` keyword in `argparse.add_argument`.
**Note:** The choice type was previously named `Choices`. This is deprecated in favor of the
[`Literal` type](https://mypy.readthedocs.io/en/stable/literal_types.html) introduced in Python 3.8 and back-ported to
3.6 and 3.7 in the `typing_extensions` library. `Choices` was removed since version 0.4.0.
- **Enum types** derived from `enum.Enum`. It is recommended to use `argtyped.Enum` which uses the instance names as
values:
```python
from argtyped import Enum
class MyEnum(Enum):
Debug = auto() # "debug"
Info = auto() # "info"
Warning = auto() # "warning"
```
- **Switch types** `Switch`. `Switch` arguments are like `bool` arguments, but they don't take values. Instead, a switch
argument `switch` requires `--switch` to enable and `--no-switch` to disable:
```python
from argtyped import Arguments, Switch
class MyArgs(Arguments):
switch: Switch = True
bool_arg: bool = False
# argv: [] => flag=True, bool_arg=False
# argv: ["--switch", "--bool-arg=false"] => flag=True, bool_arg=False
# argv: ["--no-switch", "--bool-arg=true"] => flag=False, bool_arg=True
# argv: ["--switch=false"] => WRONG
# argv: ["--no-bool-arg"] => WRONG
```
- **List types** `List[T]`, where `T` is any supported type except switch types. List arguments allow passing multiple
values on the command line following the argument flag, it is equivalent to setting `nargs="*"` in `argparse`.
Although there is no built-in support for other `nargs` settings such as `"+"` (one or more) or `N` (fixed number),
you can add custom validation logic by overriding the `__init__` method in your `Arguments` subclass.
- **Optional types** `Optional[T]`, where `T` is any supported type except list or switch types. An optional argument
will be filled with `None` if no value is provided. It could also be explicitly set to `None` by using `none` as value
in the command line:
```python
from argtyped import Arguments
from typing import Optional
class MyArgs(Arguments):
opt_arg: Optional[int] # implicitly defaults to `None`
# argv: [] => opt_arg=None
# argv: ["--opt-arg=1"] => opt_arg=1
# argv: ["--opt-arg=none"] => opt_arg=None
```
- Any other type that takes a single `str` as `__init__` parameters. It is also theoretically possible to use a function
that takes an `str` as input, but it's not recommended as it's not type-safe.
## Composing `Arguments` Classes
You can split your arguments into separate `Arguments` classes and then compose them together by inheritance. A subclass
will have the union of all arguments in its base classes. If the subclass contains an argument with the same name as an
argument in a base class, then the subclass definition takes precedence. For example:
```python
class BaseArgs(Arguments):
a: int = 1
b: Switch = True
class DerivedArgs(BaseArgs):
b: str
# args = DerivedArgs([]) # bad; `b` is required
args = DerivedArgs(["--b=1234"])
```
**Caveat:** For simplicity, we do not completely follow the [C3 linearization algorithm](
https://en.wikipedia.org/wiki/C3_linearization) that determines the class MRO in Python. Thus, it is a bad idea to have
overridden arguments in cases where there's diamond inheritance.
If you don't understand the above, that's fine. Just note that generally, it's a bad idea to have too complicated
inheritance relationships with overridden arguments.
## Argument Naming Styles
By default `argtyped` uses `--kebab-case` (with hyphens connecting words), which is the convention for UNIX command line
tools. However, many existing tools use the awkward `--snake_case` (with underscores connecting words), and sometimes
consistency is preferred over aesthetics. If you want to use underscores, you can do so by setting `underscore=True`
inside the parentheses where you specify base classes, like this:
```python
class UnderscoreArgs(Arguments, underscore=True):
underscore_arg: int
underscore_switch: Switch = True
args = UnderscoreArgs(["--underscore_arg", "1", "--no_underscore_switch"])
```
The underscore settings only affect arguments defined in the class scope; (non-overridden) inherited arguments are not
affects. Thus, you can mix-and-match `snake_case` and `kebab-case` arguments:
```python
class MyArgs(UnderscoreArgs):
kebab_arg: str
class MyFinalArgs(MyArgs, underscore=True):
new_underscore_arg: float
args = MyArgs(["--underscore_arg", "1", "--kebab-arg", "kebab", "--new_underscore_arg", "1.0"])
```
## Notes
- Advanced `argparse` features such as subparsers, groups, argument lists, and custom actions are not supported.
- Using switch arguments may result in name clashes: if a switch argument has name `arg`, there can be no argument with
the name `no_arg`.
- Optional types:
- `Optional` can be used with `Literal`:
```python
from argtyped import Arguments
from typing import Literal, Optional
class MyArgs(Arguments):
foo: Optional[Literal["a", "b"]] # valid
bar: Literal["a", "b", "none"] # also works but is less obvious
```
- `Optional[str]` would parse a value of `"none"` (case-insensitive) into `None`.
- List types:
- `List[Optional[T]]` is a valid type. For example:
```python
from argtyped import Arguments
from typing import List, Literal, Optional
class MyArgs(Arguments):
foo: List[Optional[Literal["a", "b"]]] = ["a", None, "b"] # valid
# argv: ["--foo", "a", "b", "none", "a", "b"] => foo=["a", "b", None, "a", "b"]
```
- List types cannot be nested inside a list or an optional type. Types such as `Optional[List[int]]` and
`List[List[int]]` are not accepted.
## Under the Hood
This is what happens under the hood:
1. When a subclass of `argtyped.Arguments` is constructed, type annotations and class-level attributes (i.e., the
default values) are collected to form argument declarations.
2. After verifying the validity of declared arguments, `argtyped.ArgumentSpec` are created for each argument and stored
within the subclass as the `__arguments__` class attribute.
3. When an instance of the subclass is initialized, if it's the first time, an instance of `argparse.ArgumentParser` is
created and arguments are registered with the parser. The parser is cached in the subclass as the `__parser__`
attribute.
4. The parser's `parse_args` method is invoked with either `sys.argv` or strings provided as parameters, returning
parsed arguments.
5. The parsed arguments are assigned to `self` (the instance of the `Arguments` subclass being initialized).
## Todo
- [ ] Support `action="append"` or `action="extend"` for `List[T]` types.
- Technically this is not a problem, but there's no elegant way to configure whether this behavior is desired.
- [ ] Throw (suppressible) warnings on using non-type callables as types.
- [ ] Support converting an `attrs` class into `Arguments`.
- [ ] Support forward references in type annotations.
MIT License
Copyright (c) 2020 Zecong Hu
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
نیازمندی
| مقدار | نام |
|---|---|
| >=0.7.1 | typing-inspect |
| ==2.13.9 | pylint |
| ==22.6.0 | black |
| ==5.10.1 | isort |
| ==0.961 | mypy |
| - | pytest |
| - | pytest-cov |
زبان مورد نیاز
| مقدار | نام |
|---|---|
| >=3.6 | Python |
نحوه نصب
نصب پکیج whl argtyped-0.4.0:
pip install argtyped-0.4.0.whl
نصب پکیج tar.gz argtyped-0.4.0:
pip install argtyped-0.4.0.tar.gz