Scriptic

A minimalist, embeddable Python REPL with zero external dependencies.

Features

• Zero Dependencies: Uses only the Python standard library
• Lightweight: Single file implementation (~300 lines of code)
• Embeddable: Easily integrate into any Python application
• Extensible: Add custom commands with simple decorators
• Context Injection: Share your application objects with the REPL
• Multiline Support: Properly handles functions, classes, and blocks
• Signal Handling: Gracefully manages keyboard interrupts
• Command History: Up/down arrow navigation (when readline is available)

Installation

Simply copy scriptic.py into your project:

# From GitHub
curl -O https://raw.githubusercontent.com/LayerDynamics/scriptic/main/scriptic.py

# Or just copy the file directly to your project

Basic Usage

from scriptic import run_scriptic

# Start a basic REPL
run_scriptic(intro="Welcome to Scriptic!")

Embedding in Your Application

from scriptic import Scriptic

# Create your application objects
my_app = MyApplication()

# Set up the REPL context with your objects
context = {
    "app": my_app,
    "do_something": my_app.do_something,
}

# Create and configure the REPL
repl = Scriptic(
    context=context,
    prompt="myapp> ",
    intro="MyApp Console - Type commands or %help"
)

# Add custom commands
def cmd_status(args):
    """Show the application status."""
    print(f"App status: {my_app.get_status()}")
    
repl.register_command("status", cmd_status)

# Run the REPL
repl.run()

Built-in Commands

Scriptic comes with several built-in commands:

• %help - Display help for available commands
• %exit or %quit - Exit the REPL
• %vars - Show variables in the current context
• %reset - Reset the REPL context to initial state
• %run - Execute a Python file in the current context
• %load - Load a Python file into the buffer without executing it

Adding Custom Commands

Custom commands start with % and can take arguments:

def cmd_greet(args):
    """Greet a person by name.
    
    Usage: %greet [name]
    """
    name = args.strip() or "World"
    print(f"Hello, {name}!")

repl.register_command("greet", cmd_greet)

In the REPL, you can call this with:

>>> %greet Alice
Hello, Alice!

Advanced Usage

Executing Python Files

Scriptic includes built-in support for running and loading Python files:

# In the REPL, execute a Python file in the current context
>>> %run script.py arg1 arg2

# The script.py file can access sys.argv as usual
# sys.argv[0] will be 'script.py'
# sys.argv[1] will be 'arg1'
# sys.argv[2] will be 'arg2'

# All definitions from the script become available in the REPL
>>> my_function_from_script()

# Load a file into the buffer without executing it
>>> %load another_script.py
# The file content will be displayed and added to the buffer
# You can edit it before executing

These commands make it easy to work with external Python files while maintaining the interactive nature of the REPL environment.

Customizing Signal Handling

Override the _handle_signal method for custom behavior:

class MyREPL(Scriptic):
    def _handle_signal(self, sig, frame):
        if sig == signal.SIGINT:
            print("\nDo you want to exit? (y/n)")
            if input().lower() == 'y':
                self.running = False
            else:
                self.buffer = []  # Clear input buffer

Example Application

See example.py for a complete demonstration of embedding Scriptic in a simple application.

License

MIT License - Feel free to use and modify as needed!