Prompt

Bases: ActionsHandler

Source code in pzp/prompt.py
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class Prompt(ActionsHandler):
    def __init__(
        self,
        default: Optional[Any] = None,
        prompt_str: str = "",
        type: Optional[Any] = None,
        value_proc: Optional[Callable[[str], Any]] = None,
        keys_binding: Optional[KeysBinding] = None,
        output_stream: TextIO = sys.stderr,
    ):
        """
        Initializate Prompt object

        Args:
            default: The default value to use if no input happens
            prompt_str: The input prompt
            type: The type to use to check the value against
            value_proc: Type conversion function
            keys_binding: Custom keys binding
            output_stream: Output stream
        """
        super().__init__(keys_binding=keys_binding)
        self.default = default
        self.prompt_str = prompt_str
        self.output_stream = output_stream
        if value_proc is not None:
            self.value_proc: Optional[Callable[[str], Any]] = value_proc
        elif (type is not None) or (default is not None and not isinstance(default, str)):
            from click.types import convert_type

            self.value_proc = convert_type(type, default)
        else:
            self.value_proc = None

    def setup(self, input: Optional[str] = None) -> None:
        """
        Setup Prompt execution

        Args:
            input: initial string
        """
        self.line_editor = LineEditor(line=input or "", keys_handler=self.keys_handler)
        self.screen = Screen(stream=self.output_stream, fullscreen=False)
        self.update_screen()

    def show(self, input: Optional[str] = None) -> Any:
        """
        Open pzp and return the selected element

        Args:
            input: initial string

        Raises:
            AcceptAction: Raises when the user presses a key that is mapped to the "accept" action.
            AbortAction: Raises when the user presses a key that is mapped to the "abort" action.
            CustomAction: Raises when the user presses a key that is mapped to the "custom" action.
        """
        self.setup(input=input)
        while True:
            self.process_key()
            self.update_screen()

    def process_key(self, ch: Optional[str] = None) -> None:
        "Process the pressed key"
        key_event = self.keys_handler.get_key_event(ch)
        try:
            self.line_editor.process_key_event(key_event)
        except MissingHander:
            try:
                self.process_key_event(key_event)
            except MissingHander:
                raise CustomAction(
                    action=key_event.action,  # type: ignore
                    ch=key_event.ch,
                    selected_item=self.prepare_result(),
                    line=self.line_editor.line,
                )

    def update_screen(self) -> None:
        "Update the screen"
        self.screen.write("\r").erase_line()
        self.screen.erase_line().write(self.prompt_str).reset()
        self.line_editor.print(self.screen)
        self.screen.flush()

    def prepare_result(self) -> Any:
        "Return the line converted to the correct type or the default value if the line is empty"
        if not self.line_editor.line:
            return self.default
        elif self.value_proc is not None:
            # value_proc raises an exception if the value is invalid
            return self.value_proc(self.line_editor.line)
        else:
            return self.line_editor.line

    @Action("accept", keys=["enter"])
    def accept(self, key_event: KeyEvent) -> None:
        "Confirm"
        try:
            selected_item = self.prepare_result()
        except Exception as ex:
            self.screen.write(f"\nError: The value you entered was invalid: {ex}\n")
            self.screen.move_up(2)
            self.screen.flush()
            return
        raise AcceptAction(action="accept", ch=key_event.ch, selected_item=selected_item, line=self.line_editor.line)

    @Action("abort", keys=["ctrl-c", "ctrl-g", "ctrl-q", "esc"])
    def abort(self, key_event: KeyEvent) -> None:
        "Cancel"
        raise AbortAction(action="abort", ch=key_event.ch, line=self.line_editor.line)

    @Action("ignore", keys=["null", "insert"])
    def ignore(self) -> None:
        "Do nothing"
        pass

__init__(default=None, prompt_str='', type=None, value_proc=None, keys_binding=None, output_stream=sys.stderr)

Initializate Prompt object

Parameters:
  • default (Optional[Any], default: None ) –

    The default value to use if no input happens

  • prompt_str (str, default: '' ) –

    The input prompt

  • type (Optional[Any], default: None ) –

    The type to use to check the value against

  • value_proc (Optional[Callable[[str], Any]], default: None ) –

    Type conversion function

  • keys_binding (Optional[KeysBinding], default: None ) –

    Custom keys binding

  • output_stream (TextIO, default: stderr ) –

    Output stream

Source code in pzp/prompt.py
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def __init__(
    self,
    default: Optional[Any] = None,
    prompt_str: str = "",
    type: Optional[Any] = None,
    value_proc: Optional[Callable[[str], Any]] = None,
    keys_binding: Optional[KeysBinding] = None,
    output_stream: TextIO = sys.stderr,
):
    """
    Initializate Prompt object

    Args:
        default: The default value to use if no input happens
        prompt_str: The input prompt
        type: The type to use to check the value against
        value_proc: Type conversion function
        keys_binding: Custom keys binding
        output_stream: Output stream
    """
    super().__init__(keys_binding=keys_binding)
    self.default = default
    self.prompt_str = prompt_str
    self.output_stream = output_stream
    if value_proc is not None:
        self.value_proc: Optional[Callable[[str], Any]] = value_proc
    elif (type is not None) or (default is not None and not isinstance(default, str)):
        from click.types import convert_type

        self.value_proc = convert_type(type, default)
    else:
        self.value_proc = None

abort(key_event)

Cancel

Source code in pzp/prompt.py
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@Action("abort", keys=["ctrl-c", "ctrl-g", "ctrl-q", "esc"])
def abort(self, key_event: KeyEvent) -> None:
    "Cancel"
    raise AbortAction(action="abort", ch=key_event.ch, line=self.line_editor.line)

accept(key_event)

Confirm

Source code in pzp/prompt.py
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@Action("accept", keys=["enter"])
def accept(self, key_event: KeyEvent) -> None:
    "Confirm"
    try:
        selected_item = self.prepare_result()
    except Exception as ex:
        self.screen.write(f"\nError: The value you entered was invalid: {ex}\n")
        self.screen.move_up(2)
        self.screen.flush()
        return
    raise AcceptAction(action="accept", ch=key_event.ch, selected_item=selected_item, line=self.line_editor.line)

ignore()

Do nothing

Source code in pzp/prompt.py
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@Action("ignore", keys=["null", "insert"])
def ignore(self) -> None:
    "Do nothing"
    pass

prepare_result()

Return the line converted to the correct type or the default value if the line is empty

Source code in pzp/prompt.py
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def prepare_result(self) -> Any:
    "Return the line converted to the correct type or the default value if the line is empty"
    if not self.line_editor.line:
        return self.default
    elif self.value_proc is not None:
        # value_proc raises an exception if the value is invalid
        return self.value_proc(self.line_editor.line)
    else:
        return self.line_editor.line

process_key(ch=None)

Process the pressed key

Source code in pzp/prompt.py
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def process_key(self, ch: Optional[str] = None) -> None:
    "Process the pressed key"
    key_event = self.keys_handler.get_key_event(ch)
    try:
        self.line_editor.process_key_event(key_event)
    except MissingHander:
        try:
            self.process_key_event(key_event)
        except MissingHander:
            raise CustomAction(
                action=key_event.action,  # type: ignore
                ch=key_event.ch,
                selected_item=self.prepare_result(),
                line=self.line_editor.line,
            )

setup(input=None)

Setup Prompt execution

Parameters:
  • input (Optional[str], default: None ) –

    initial string

Source code in pzp/prompt.py
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def setup(self, input: Optional[str] = None) -> None:
    """
    Setup Prompt execution

    Args:
        input: initial string
    """
    self.line_editor = LineEditor(line=input or "", keys_handler=self.keys_handler)
    self.screen = Screen(stream=self.output_stream, fullscreen=False)
    self.update_screen()

show(input=None)

Open pzp and return the selected element

Parameters:
  • input (Optional[str], default: None ) –

    initial string

Raises:
  • AcceptAction

    Raises when the user presses a key that is mapped to the "accept" action.

  • AbortAction

    Raises when the user presses a key that is mapped to the "abort" action.

  • CustomAction

    Raises when the user presses a key that is mapped to the "custom" action.

Source code in pzp/prompt.py
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def show(self, input: Optional[str] = None) -> Any:
    """
    Open pzp and return the selected element

    Args:
        input: initial string

    Raises:
        AcceptAction: Raises when the user presses a key that is mapped to the "accept" action.
        AbortAction: Raises when the user presses a key that is mapped to the "abort" action.
        CustomAction: Raises when the user presses a key that is mapped to the "custom" action.
    """
    self.setup(input=input)
    while True:
        self.process_key()
        self.update_screen()

update_screen()

Update the screen

Source code in pzp/prompt.py
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def update_screen(self) -> None:
    "Update the screen"
    self.screen.write("\r").erase_line()
    self.screen.erase_line().write(self.prompt_str).reset()
    self.line_editor.print(self.screen)
    self.screen.flush()