To run the Python interpreter in a script

Have you ever wanted to ** run an interpreter in a Python script **? You can use the functions and classes you created from the beginning, and you can also execute ordinary Python code. Isn't it nice!

Basics

In Python, there is a ** standard library ** called code.py that can run the interpreter.

`myconsole.py`


import code
console = code.InteractiveConsole(locals=locals()) # <- locals=locals()Important
console.interact()

Write like this. Here, code.InteractiveConsole is given the argumentlocals = locals (), but locals () is a ** function that returns all the values of the variables in the ** local area of itself (here in the script) in dictionary format. By giving this as an argument, ** functions in the script etc. are passed to the started python interpreter **

When you run this script,

$ python myconsole.py
Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>>

This is how the Python interpreter runs!

Advanced version

I used this code.py this way.

`color.py`


import code


def split_code(colorcode, sep=2):

    for index, letter in enumerate(colorcode, start=1):
        if index == 1:
            continue

        elif index % sep == 0:
            yield colorcode[index-sep:index]


def get_rgb(colorcode):

    result = []

    for element in split_code(colorcode):
        result.append( int(element, 16) )

    return result

def get_colorcode(r, g, b):

    code = hex(r) + hex(g) + hex(b)

    result = list(split_code(code))

    return "".join(result[1::2])


if __name__ == "__main__":

    code.InteractiveConsole(locals=locals()).interact()

This python script has a function to convert the color code. When I run this script ...

$ python color.py
Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> dir()
['__builtins__', '__doc__', '__file__', '__name__', '__package__', 'split_code', 'code', 'get_colorcode', 'get_rgb']
>>>

In this way, the Python interpreter is started, and you can use the created function ** without importing anything. The reason you don't have to import anything is because the above code says locals = locals ().

If you didn't set locals = locals () here,

Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> dir()
['__builtins__', '__doc__', '__name__']
>>>

This makes it impossible to use the functions in the script.

Reference link

29.1. code — Interpreter base class (python2.7)
30.1. code — Interpreter base class (python3.5)

Run the Python interpreter in a script