from typing import Any, Generic, List, Optional, TextIO, TypeVar, Union, overload from . import get_console from .console import Console from .text import Text, TextType PromptType = TypeVar("PromptType") DefaultType = TypeVar("DefaultType") class PromptError(Exception): """Exception base class for prompt related errors.""" class InvalidResponse(PromptError): """Exception to indicate a response was invalid. Raise this within process_response() to indicate an error and provide an error message. Args: message (Union[str, Text]): Error message. """ def __init__(self, message: TextType) -> None: self.message = message def __rich__(self) -> TextType: return self.message class PromptBase(Generic[PromptType]): """Ask the user for input until a valid response is received. This is the base class, see one of the concrete classes for examples. Args: prompt (TextType, optional): Prompt text. Defaults to "". console (Console, optional): A Console instance or None to use global console. Defaults to None. password (bool, optional): Enable password input. Defaults to False. choices (List[str], optional): A list of valid choices. Defaults to None. show_default (bool, optional): Show default in prompt. Defaults to True. show_choices (bool, optional): Show choices in prompt. Defaults to True. """ response_type: type = str validate_error_message = "[prompt.invalid]Please enter a valid value" illegal_choice_message = ( "[prompt.invalid.choice]Please select one of the available options" ) prompt_suffix = ": " choices: Optional[List[str]] = None def __init__( self, prompt: TextType = "", *, console: Optional[Console] = None, password: bool = False, choices: Optional[List[str]] = None, show_default: bool = True, show_choices: bool = True, ) -> None: self.console = console or get_console() self.prompt = ( Text.from_markup(prompt, style="prompt") if isinstance(prompt, str) else prompt ) self.password = password if choices is not None: self.choices = choices self.show_default = show_default self.show_choices = show_choices @classmethod @overload def ask( cls, prompt: TextType = "", *, console: Optional[Console] = None, password: bool = False, choices: Optional[List[str]] = None, show_default: bool = True, show_choices: bool = True, default: DefaultType, stream: Optional[TextIO] = None, ) -> Union[DefaultType, PromptType]: ... @classmethod @overload def ask( cls, prompt: TextType = "", *, console: Optional[Console] = None, password: bool = False, choices: Optional[List[str]] = None, show_default: bool = True, show_choices: bool = True, stream: Optional[TextIO] = None, ) -> PromptType: ... @classmethod def ask( cls, prompt: TextType = "", *, console: Optional[Console] = None, password: bool = False, choices: Optional[List[str]] = None, show_default: bool = True, show_choices: bool = True, default: Any = ..., stream: Optional[TextIO] = None, ) -> Any: """Shortcut to construct and run a prompt loop and return the result. Example: >>> filename = Prompt.ask("Enter a filename") Args: prompt (TextType, optional): Prompt text. Defaults to "". console (Console, optional): A Console instance or None to use global console. Defaults to None. password (bool, optional): Enable password input. Defaults to False. choices (List[str], optional): A list of valid choices. Defaults to None. show_default (bool, optional): Show default in prompt. Defaults to True. show_choices (bool, optional): Show choices in prompt. Defaults to True. stream (TextIO, optional): Optional text file open for reading to get input. Defaults to None. """ _prompt = cls( prompt, console=console, password=password, choices=choices, show_default=show_default, show_choices=show_choices, ) return _prompt(default=default, stream=stream) def render_default(self, default: DefaultType) -> Text: """Turn the supplied default in to a Text instance. Args: default (DefaultType): Default value. Returns: Text: Text containing rendering of default value. """ return Text(f"({default})", "prompt.default") def make_prompt(self, default: DefaultType) -> Text: """Make prompt text. Args: default (DefaultType): Default value. Returns: Text: Text to display in prompt. """ prompt = self.prompt.copy() prompt.end = "" if self.show_choices and self.choices: _choices = "/".join(self.choices) choices = f"[{_choices}]" prompt.append(" ") prompt.append(choices, "prompt.choices") if ( default != ... and self.show_default and isinstance(default, (str, self.response_type)) ): prompt.append(" ") _default = self.render_default(default) prompt.append(_default) prompt.append(self.prompt_suffix) return prompt @classmethod def get_input( cls, console: Console, prompt: TextType, password: bool, stream: Optional[TextIO] = None, ) -> str: """Get input from user. Args: console (Console): Console instance. prompt (TextType): Prompt text. password (bool): Enable password entry. Returns: str: String from user. """ return console.input(prompt, password=password, stream=stream) def check_choice(self, value: str) -> bool: """Check value is in the list of valid choices. Args: value (str): Value entered by user. Returns: bool: True if choice was valid, otherwise False. """ assert self.choices is not None return value.strip() in self.choices def process_response(self, value: str) -> PromptType: """Process response from user, convert to prompt type. Args: value (str): String typed by user. Raises: InvalidResponse: If ``value`` is invalid. Returns: PromptType: The value to be returned from ask method. """ value = value.strip() try: return_value: PromptType = self.response_type(value) except ValueError: raise InvalidResponse(self.validate_error_message) if self.choices is not None and not self.check_choice(value): raise InvalidResponse(self.illegal_choice_message) return return_value def on_validate_error(self, value: str, error: InvalidResponse) -> None: """Called to handle validation error. Args: value (str): String entered by user. error (InvalidResponse): Exception instance the initiated the error. """ self.console.print(error) def pre_prompt(self) -> None: """Hook to display something before the prompt.""" @overload def __call__(self, *, stream: Optional[TextIO] = None) -> PromptType: ... @overload def __call__( self, *, default: DefaultType, stream: Optional[TextIO] = None ) -> Union[PromptType, DefaultType]: ... def __call__(self, *, default: Any = ..., stream: Optional[TextIO] = None) -> Any: """Run the prompt loop. Args: default (Any, optional): Optional default value. Returns: PromptType: Processed value. """ while True: self.pre_prompt() prompt = self.make_prompt(default) value = self.get_input(self.console, prompt, self.password, stream=stream) if value == "" and default != ...: return default try: return_value = self.process_response(value) except InvalidResponse as error: self.on_validate_error(value, error) continue else: return return_value class Prompt(PromptBase[str]): """A prompt that returns a str. Example: >>> name = Prompt.ask("Enter your name") """ response_type = str class IntPrompt(PromptBase[int]): """A prompt that returns an integer. Example: >>> burrito_count = IntPrompt.ask("How many burritos do you want to order") """ response_type = int validate_error_message = "[prompt.invalid]Please enter a valid integer number" class FloatPrompt(PromptBase[int]): """A prompt that returns a float. Example: >>> temperature = FloatPrompt.ask("Enter desired temperature") """ response_type = float validate_error_message = "[prompt.invalid]Please enter a number" class Confirm(PromptBase[bool]): """A yes / no confirmation prompt. Example: >>> if Confirm.ask("Continue"): run_job() """ response_type = bool validate_error_message = "[prompt.invalid]Please enter Y or N" choices: List[str] = ["y", "n"] def render_default(self, default: DefaultType) -> Text: """Render the default as (y) or (n) rather than True/False.""" yes, no = self.choices return Text(f"({yes})" if default else f"({no})", style="prompt.default") def process_response(self, value: str) -> bool: """Convert choices to a bool.""" value = value.strip().lower() if value not in self.choices: raise InvalidResponse(self.validate_error_message) return value == self.choices[0] if __name__ == "__main__": # pragma: no cover from pip._vendor.rich import print if Confirm.ask("Run [i]prompt[/i] tests?", default=True): while True: result = IntPrompt.ask( ":rocket: Enter a number between [b]1[/b] and [b]10[/b]", default=5 ) if result >= 1 and result <= 10: break print(":pile_of_poo: [prompt.invalid]Number must be between 1 and 10") print(f"number={result}") while True: password = Prompt.ask( "Please enter a password [cyan](must be at least 5 characters)", password=True, ) if len(password) >= 5: break print("[prompt.invalid]password too short") print(f"password={password!r}") fruit = Prompt.ask("Enter a fruit", choices=["apple", "orange", "pear"]) print(f"fruit={fruit!r}") else: print("[b]OK :loudly_crying_face:")