Climax Prompt

Python package for creating cli prompts.

This package exports 2 classes that contain the majority of its primary functionality. The Prompt and StringPrompt classes. The main difference between the 2 is that StringPrompts only processes strings while Prompts can process any arbitrary type.

The StringPrompt.exec_string_input_loop and Prompt.exec_input_loop methods of each class create a loop that prompts a user for input and will reprompt until either valid input is inputted or an exception is raised when converting the input string. If valid input is inputted then the inputted string or value (if the string is converted to a non string value) is returned.

Usage Examples

StringPrompt Usage Example

from climax.prompt import StringPrompt, StringPromptInput


# string validator gets passed a tuple containing the formatted and original
# unformatted string input
def is_palindrome(string: StringPromptInput) -> str | None:
    return (
        f'Provided input is not a palindrome: "{string.original}"\n'
        if len(string.formatted) == 0 or string.formatted != string.formatted[::-1]
        else None
    )


palindrome_prompt = StringPrompt(
    "Input a palindrome...\n",
    string_validator=is_palindrome,
    formatter=lambda a_string: a_string.strip().lower(),
    ps1=">>> ",
)

# once validation passes the formatted and original unformatted string input
# gets returned
formatted_palindrome_string_input, original_palindrome_string_input = palindrome_prompt.exec_string_input_loop()

print(f'You inputted the palindrome: "{formatted_palindrome_string_input}"')

Calling the StringPrompt.exec_string_input_loop method will result in the following process:

1. The StringPrompt.message to be printed to stdout followed by the StringPrompt.ps1 if set.

2. The string inputted to stdin then gets passed to the StringPrompt.formatter(str).

3. The formatted and raw unformatted original input string then gets passed to the StringPrompt.string_validator.

4. If validation passes (the StringPrompt.string_validator returns None) then both the formatted and original unformatted string input gets returned.

5. If validation fails (the StringPrompt.string_validator returns a string error message) then the string error message gets printed to stderr and the process is repeated.

When the method in the example above is called this will result in the following prompt in the terminal:

Input a palindrome...
>>> slITher                                   # simulated user input
Provided input is not a palindrome: "slITher" # original unformatted string used in error message
Input a palindrome...
>>> levEl                                     # simulated user input
You inputted the palindrome: "level"          # formatted input used for validation and in this message

Prompt Usage Example

from typing import assert_never

from climax.prompt import (
    Prompt,
    PromptResultFailure,
    PromptResultSuccess,
    StringPromptInput,
)


# string validator gets passed a tuple containing the formatted and original
# unformatted string input
def string_is_integer(string: StringPromptInput) -> str | None:
    start_index = 1 if string.formatted.startswith("-") or string.formatted.startswith("+") else 0

    return (
        None
        if string.formatted[start_index:].isdecimal()
        else f'Provided input is not an integer: "{string.formatted}"\n'
    )


# validator gets passed whatever the string input gets converted to
def is_positive_even_integer(integer: int) -> str | None:
    if integer <= 0:
        return f"Integer isn't positive: {integer}\n"

    if integer % 2 != 0:
        return f"Integer isn't even: {integer}\n"

    return None


positive_even_integer_prompt = Prompt[int].create(
    "Input a positive even integer: ",
    int,  # can pass any function/lambda that consumes a string and outputs the specified type
    validator=is_positive_even_integer,
    string_validator=string_is_integer,
    formatter=str.strip,
)

positive_even_integer_prompt_result = positive_even_integer_prompt.exec_input_loop()

# The result is a union of two classes. The type checker narrows the type in
# each case, so `value` is only available on the successful conversion and
# `conversion_exception` is only available on the failed conversion.
match positive_even_integer_prompt_result:
    case PromptResultFailure(
        original_input_string=original_input_string,
        conversion_exception=conversion_exception,
    ):
        print(f'Error converting input to an int: "{original_input_string}"\n\n{repr(conversion_exception)}')
    case PromptResultSuccess(value=value):
        print("You inputted the positive even integer:", value)
    case _:
        assert_never(positive_even_integer_prompt_result)

Calling the Prompt.exec_input_loop method will result in the same process outlined above when StringPrompt.exec_string_input_loop is called, except it performs additional conversion of the string input and validation on that converted string input as outlined below if string input validation passes (otherwise the reprompt process is identical):

1. The formatted validated string input is passed to the Prompt.converter(str).

2. If an exception occurs during conversion, then a PromptResultFailure is returned with the original input string and the Exception that was raised.

3. If conversion succeeds, the converted string input value is then passed to the Prompt.validator.

4. If validation passes (the Prompt.validator returns None) then a PromptResultSuccess containing the original input string and its converted value is returned.

5. If validation fails (the Prompt.validator returns a string error message) then the error message gets printed to stderr and the process is repeated.

When the method in the example above is called this will result in the following prompt in the terminal:

Input a positive even integer:    sliTHer          # simulated user input
Provided input is not an integer: "slither"        # formatted string input is used in this message
Input a positive even integer: -34                 # simulated user input
Integer isn't positive: -34
Input a positive even integer: 7                   # simulated user input
Integer isn't even: 7
Input a positive even integer: 22                  # simulated user input
You inputted the positive even integer: 22

Installing Package

This package is available on PyPI and can be installed via any of the standard methods:

# via poetry
poetry add climax-prompt

# via uv
uv add climax-prompt

# via pip
pip install climax-prompt

Repo

The next sections cover details and info about this git repository. If you're just importing this package as a dependency in a python project then it probably doesn't apply to you. If you clone this repo, especially if you intend to make a pr, then they're relevant.

Tooling Tasks

The repo for this project uses ruff and mypy for linting, ruff for formatting, pytest for testing, and sphinx (with numpydoc) for generating API documentation.

All repo tasks can be executed via the make targets listed below:

• all - Run build.
• bandit - Scan source code for security issues with bandit.
• build - Build distributable artifacts.
• clean - Remove build output and generated docs files.
• clean-all - Run clean and clean-cache.
• clean-cache - Remove tool caches and __pycache__ directories.
• format - Fix lint issues and format code with ruff.
• lint - Run all lint and type checks.
• mypy - Type check with mypy.
• poetry-check - Validates content of pyproject.toml and poetry.lock.
• readme - Generate source/README.rst by using pandoc to convert the root README.md to rst.
• ruff-check - Lint with ruff.
• ruff-format-check - Check formatting with ruff.
• serve-docs - Build and serve html API docs on 127.0.0.1:8000.
• serve-tests - Build and serve html test results and coverage reports on 127.0.0.1:8000 and 127.0.0.1:8001. Depends on parallel.
• setup - Install dependencies and pre-commit hooks. This should be run right after cloning the repo.
• smoke - Install the built wheel and sdist in clean venvs and run smoke tests. The wheel and sdist artifacts must be built before running this target.
• test - Run tests with terminal results and coverage report.
• test-html - Run tests with html results and coverage reports.
• test-xml - Run test with xml results and coverage reports.

In addition to the make targets listed above, all sphinx make targets are available and valid as well.

Remotes

The primary remote repo for this package is hosted on gitlab, but is also mirrored to codeberg and github.

MIT License

This package is licensed under the MIT license and can be found in LICENSE.txt.