cliify 0.1.3

Package for creating a CLI from classes

A flexible Python package for building command-line interfaces with object hierarchies, auto-completion, and dynamic parameter validation.

Features

• Object-oriented command structure

• Nested command hierarchies using subparsers

• Type hints and automatic type conversion

• Dynamic command completion

• Parameter validation and auto-completion

• Caching for improved performance

• Expression evaluation support

Installation

pip install cliify

Quick Start

Here’s a simple example showing the command parsing:

from cliify import command, commandParser

@commandParser
class Calculator:
    def getValidOperations(self):
        return ['+', '-', '*', '/']

    @command(completions={'operation': lambda self: self.getValidOperations()})
    def calculate(self, a: int, operation: str, b: int):
        """
        Calculate the result of an operation

        Args:
            a: First operand
            operation: Operation to perform
            b: Second operand

        """

        if operation == '+':
            return a + b
        elif operation == '-':
            return a - b
        elif operation == '*':
            return a * b
        elif operation == '/':
            return a / b

calc = Calculator()
#can use positional or named arguments
result = calc.parseCommand("calculate 5 + 3")  # Returns 8
result = calc.parseCommand("calculate a: 5, operation: + , b: 3")  # Returns 8
help = calc.getHelp("calculate")   # Return help message from docstring

Nested Commands

You can create hierarchical command structures with subparserss (supports single object or a dictionary of objects):

@commandParser()
class Device:
    def __init__(self, name):
        self.name = name
        self.value = 0

    @command(completions={'value': [0, 1, 2, 3, 4, 5]})
    def setValue(self, value: int):
        self.value = value


@commandParser(subparsers=['devices'])
class Controller:
    def __init__(self):

        self.devices = {}

        self.singleDevice = Device("singleDevice")

    @command(help="Add a new device")               #help message can also be explicitly set
    def addDevice(self, name: str):
        self.devices[name] = Device(name)

    # Devices can have their own commands
    class DeviceCommands:
        @command(help="Set device value", completions={'value': [0, 1, 2, 3, 4, 5]})
        def setValue(self, value: int):
            self.value = value


controller = Controller()

result = controller.parseCommand("addDevice device1")
result = controller.parseCommand("device1.setValue 3")
result = controller.parseCommand("singleDevice.setValue 3")

Dynamic Completions

The package supports various ways to define completions:

1. Static Lists:

class myController:

    self.mode = None
    self.min_value = 0
    self.max_value = 10

    #static list of values
    @command(completions={'mode': ['auto', 'manual', 'hybrid']})
    def setMode(self, mode: str):
        self.mode = mode

    def getAvailablePorts(self):
        return ['COM1', 'COM2', 'COM3']

    #method reference
    @command(completions={'port': 'getAvailablePorts'})
    def connect(self, port: str):
        self.port = port

    #lambda function
    @command(completions={'value': lambda self: range(self.min_value, self.max_value + 1)})
    def setValue(self, value: int):
        self.value = value


controller = myController()

completions = controller.getCompletions("setMode ")  # Returns ['mode']
completions = controller.getCompletions("setMode mode: ")  # Returns ['auto', 'manual', 'hybrid']

Caching and Performance

The completion tree can be cached for better performance:

controller = Controller()

# First call builds the tree
completions = controller.getCompletions("set", use_cache=True)

# Subsequent calls use cached tree
completions = controller.getCompletions("get", use_cache=True)

Use the @invalidatesTree decorator for methods that modify the command structure:

@invalidatesTree
def addCommand(self, name: str, command: Callable):
    self.commands[name] = command

Type Conversion

The parser automatically converts string inputs to the correct Python types based on type hints:

@command(help="Configure sensor")
def configureSensor(self,
                   id: int,           # Converts to integer
                   name: str,         # Handles quoted strings
                   active: bool,      # Converts to boolean
                   gains: List[float] # Converts to list of floats
                   ):
    pass

Bytes handling

bytes type arguments can handle multiple methods of input:

@command(help="Send data")
def sendData(self, data: bytes):
    pass

# Hexadecimal string
result = controller.parseCommand("sendData 0xdeadbeef")
result = controller.parseCommand("sendData 0x00 0x01 0x02")

# Base64 encoded string
result = controller.parseCommand("sendData ZGVhZGJlZWY=")

# Raw bytes
result = controller.parseCommand("sendData b'hello world'")

Expression Evaluation

Enable expression evaluation for dynamic values:

@commandParser(allow_eval=True)
class Calculator:
    @command(help="Calculate result")
    def calculate(self, value: int):
        return value

calc = Calculator()
result = calc.parseCommand("calculate $(2 * 3)")  # Evaluates expression

Out-of-the-Box UI

This package contains some out of the box support for a command line interface using prompt_toolkit. The CommandCompleter class can be used with prompt_toolkit to provide a command line interface with auto-completion and history. There are also ready-to-use UI classes for a simple command line interface and a more advanced command line interface with a command history.

The below example will create a split console app (a console with a command line interface on the bottom and a log on the top) with auto-completion and history. By default logs and print statements will be redirected to the log console.

from cliify import command, commandParser
from cliify.ui.prompt_toolkit import SplitConsole

@commandParser()
class Device:
    def __init__(self, name):
        self.name = name
        self.value = 0

    @command(completions={'value': [0, 1, 2, 3, 4, 5]})
    def setValue(self, value: int):
        self.value = value


@commandParser(subparsers=['devices'])
class Controller:
    def __init__(self):

        self.devices = {}

        self.singleDevice = Device("singleDevice")

    @command(help="Add a new device")               #help message can also be explicitly set
    def addDevice(self, name: str):
        self.devices[name] = Device(name)

    # Devices can have their own commands
    class DeviceCommands:
        @command(help="Set device value", completions={'value': [0, 1, 2, 3, 4, 5]})
        def setValue(self, value: int):
            self.value = value


controller = Controller()
app = SplitConsole(controller,"My CLI App")
app.start()

Advanced Features

1. Custom Type Conversion: - Override _convert_type for custom type handling - Support for bytes, hex strings, and more

2. Error Handling: - Type conversion errors - Missing required arguments - Invalid commands or paths

3. Command Help: - Auto-generated help from docstrings - Custom help messages per command

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License