optfunc2
Auto-generate CLI from Python functions — zero boilerplate.

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Turn any Python function into a CLI command — no argparse, no click, no boilerplate. Just add a decorator and your function's signature becomes the interface.

Why optfunc2?

	optfunc2	argparse	click	typer
Lines to add a CLI command	~1 (decorator)	~15	~8	~5
Auto-generated help from docstring	✅	❌	❌	✅
Type coercion from annotations	✅	Manual	Manual	✅
Shell abbreviation (-a for --arg)	✅	❌	❌	❌
Hex input support (0x2A)	✅	❌	❌	❌
Dependencies	1 (docstring-parser)	stdlib	click	typer+click
External dependencies	prettytable (optional)	0	7+	20+
Union types (int | float)	✅	❌	❌	✅

Install

pip install optfunc2

Quick Start

from optfunc2 import cmdline, cmdline_default, cmdline_start

@cmdline_default
def add(a: float, b: float):
    """Add two numbers

    Args:
        a: The first number
        b: The second number
    """
    print(f"{a} + {b} = {a + b}")

@cmdline
def multiply(x: int | float, y: int = 5):
    """Multiply two numbers

    Args:
        x: The first number
        y: The second number (default 5)
    """
    print(f"{x} × {y} = {x * y}")

if __name__ == "__main__":
    cmdline_start(header_doc="✨ calc CLI", has_abbrev=True)

$ python calc.py add --a 2.3 --b 3        # 2.3 + 3.0 = 5.3
$ python calc.py add -a 2.3 -b 3           # abbreviation works too
$ python calc.py multiply --x 3            # 3 × 5 = 15
$ python calc.py                           # uses default command
$ python calc.py help                      # show all commands
$ python calc.py add -h                    # show command help

Features

Decorators

Decorator	Description
@cmdline	Register a function as a CLI command
@cmdline_default	Same as above, but also the default when no command is given

Type Support

Type	Input Example	Notes
int	--n 42 or --n 0x2A	Hex format supported
float	--r 3.14
str	--name hello
bool	--verbose (no value needed)
list	--items '[1, 2, 3]'	Parsed via ast.literal_eval
dict	--cfg '{"key": "val"}'	Parsed via ast.literal_eval
int | float	--x 3 or --x 2.5	Union types supported

Argument Styles

# All of these are equivalent:
python app.py my_cmd --name hello --count 3
python app.py my_cmd --name=hello --count=3
python app.py my_cmd -n hello -c 3        # abbreviations (when has_abbrev=True)
python app.py my_cmd -nhello -c3          # abbreviation + value combined

cmdline_start() Options

cmdline_start(
    header_doc="My App",      # Header text shown in help
    has_abbrev=True,          # Enable single-char abbreviation (-a for --arg)
    print_retval=False,       # Print return value to stdout
)

called_directly()

Check if the current function was invoked by optfunc2 (vs. called by another function):

@cmdline
def main():
    if called_directly():
        print("Called from CLI")
    else:
        print("Called from another function")

Help Output

$ python calc.py help
Usage: calc.py [command] [<args>|--help]

✨ calc CLI

commands:
    add          [default] Add two numbers
    multiply     Multiply two numbers

$ python calc.py add -h
Usage: calc.py add [OPTIONS]

Add two numbers

Arguments:
+------+--------+-------+---------+------------------+
| Opt  | Abbrev |  Type | Default |      Desc       |
+------+--------+-------+---------+------------------+
| --a  |   -a   | float |         | The first number |
| --b  |   -b   | float |         | The second number|
+------+--------+-------+---------+------------------+

Real-World Example

from optfunc2 import cmdline, cmdline_default, cmdline_start
import os

@cmdline_default
def list_files(directory: str = ".", show_size: bool = False):
    """List files in a directory

    Args:
        directory: Target directory (default ".")
        show_size: Show file size in bytes
    """
    for f in os.listdir(directory):
        path = os.path.join(directory, f)
        if show_size and os.path.isfile(path):
            print(f"{f} ({os.path.getsize(path)} bytes)")
        else:
            print(f)

if __name__ == "__main__":
    cmdline_start(header_doc="📁 file manager", has_abbrev=True)

Limitations

• Variadic arguments (*args, **kwargs) are not supported
• Abbreviation conflicts (e.g., text and test both want -t) are resolved silently — first one wins
• Negative numbers as values require --arg=-1 syntax (not --arg -1)

License

PyPA License — see LICENSE.txt