expose python function to cmd in one line

util.py

"""
a lazy wrapper to export python function directly as command line interface with one line of code
"""

import click
from functools import wraps, partial
import inspect


def get_prefix(key: str, prefix_set: set):
    for i in range(1, len(key)):
        if key[:i] not in prefix_set:
            prefix_set.add(key[:i])
            return key[:i]


def parse_doc_string(f):
    """
    parse func string and return a map with param name as key and param doc as value and func description
    """
    params_name_doc_map = {}
    func_desc = ""
    if f.__doc__:
        for line in f.__doc__.split('\n'):
            if not func_desc and line:
                func_desc = line
            if line.strip().startswith(":param"):
                line = line.replace(":param", "").strip().split(":")
                if len(line) == 2:
                    params_name_doc_map[line[0]] = line[1]
    return params_name_doc_map, func_desc


def lazy_cmd(func, cli_group: click.group = None):
    signature = inspect.signature(func)
    prefix_set = set()
    param_doc_map, func_desc = parse_doc_string(func)
    f = func
    if func_desc:
        f.__doc__ = func_desc

    for k, v in signature.parameters.items():
        prefix = get_prefix(k, prefix_set)
        help_k = param_doc_map.get(k, "")
        if v.default is v.empty:
            f = click.option('-' + prefix, '--' + k, help=help_k, required=True)(f)
        else:
            f = click.option('-' + prefix, '--' + k, help=help_k, default=v.default)(f)
    if cli_group is not None:
        f = cli_group.command()(f)
    else:
        f = click.command()(f)

    @wraps(func)
    def with_lazy_option_and_cmd(*args, **kwargs):
        """
        use functions default params as click options
        :param args:
        :param kwargs:
        :return:
        """
        return f(*args, **kwargs)

    return with_lazy_option_and_cmd


@click.group()
def cli():
    pass


@partial(lazy_cmd, cli=cli)
def bar(foo):
    print("bar " + foo)


@partial(lazy_cmd, cli=cli)
def foo(bar, count=1):
    """
    func def
    :param bar: sss
    :param count: foo name
    :return:
    """
    for n in range(count):
        print(bar)


if __name__ == '__main__':
    cli()