A poor man's REPL written in Python. Guess what? No dependencies. Just fun.

repl.py

#!/usr/bin/python -i

# For implementing custom exception ahndler
import sys

# This is an error handler for badly typed input
def repl_exchandler(type, value, traceback):
    # If a name doesn't exist in the namespace
    if (type == NameError):                                                                                            
        print "Command {}. Type \"help\".".format(value)                                                               
        return
    # If the user typed something dumb
    if (type == SyntaxError):                                                                                          
        print "Bad input. Type \"help\".".format(value)                                                                
        return
    # For all other issues (like bugs in your code) get adult supervision.
    sys.__excepthook__(type, value, traceback)                                                                         

# Only do stuff if it's interactive
if sys.flags.interactive:
    # Actually override the exception handler
    sys.excepthook = repl_exchandler

    # Replace the prompt with something funny
    sys.ps1 = "[REPL]>> "

# This is the help string, which will happen when the user types "help"
help = """
  Welcome to my big fat python REPL! Here's what to do:
  command() = executes command
  
  For any questions, email edenzik@gmail.com
"""

print "Hello! Welcome to my dumb REPL in Python. If you need help, type \'help\'. Thanks for playing"