Lisp in Python, according to http://danthedev.com/2015/09/09/lisp-in-your-language/

py_lisp_repl.py

# Inspiration from [http://danthedev.com/2015/09/09/lisp-in-your-language/]
# Let's see what we can do in Python, eh?

# Lisp data structures:
# * Use ( and ) to denote lists
# * Arguments are space separated
# * First item is a function
# * Remaining items are the arguments

native = {
    '+': lambda a, b: a + b,
    '-': lambda a, b: a - b,
    '*': lambda a, b: a * b,
    '/': lambda a, b: a / b,
    '=': lambda a, b: a == b,
    'def': lambda a, b: pl_def(a, b),
    'print': lambda *a: print(''.join(str(x) for x in a)) }

global scope_dict
scope_dict = {}

def pl_def(name, value):
    global scope_dict
    scope_dict[name] = value
    return scope_dict[name]

def pl_eval(rawExpr):

    # if the expression isn't a list, return it
    if not isinstance(rawExpr, list):
        return rawExpr

    # use existing scope
    global scope_dict
    scope = scope_dict

    # resolve all our new string names from our scope
    def symbol_check(symbol):
        if isinstance(symbol, list):
            return symbol
        elif symbol in scope:
            return scope[symbol]
        else:
            return symbol
    expression = [symbol_check(x) for x in rawExpr]

    # the first item is the function or its name
    fn_name = expression[0]

    # resolve the function from native if necessary
    fn = native[fn_name] if type(fn_name) == str else fn_name

    # the remaining items are the arguments
    def apply_func(arg):
        # if this argument is an expression, treat it as code
        if isinstance(arg, list):
            return pl_eval(arg)
        else:
            return arg
    args = [apply_func(x) for x in expression[1:]]

    # call the function with these arguments
    return fn(*args)

pl_eval(['print', "Hello world!\n", "Nailed it."])
#a = pl_eval([int, 4.14])
#b = pl_eval([print, [input, "What is your name?\n> "]])
#c = pl_eval(['=', 6, 6])
#d = pl_eval(['def', 'a', 5])
#e = pl_eval(['print', ['+', 'a', 'a']])
f = pl_eval(['print', ['def', 'a', 5]])

print(f)