Here is a very basic object orientated implementation of a read evaluate print loop AKA REPL. I encluded REShell to demonstrate how one could use Reple

#-*-coding:utf8;-*- #qpy:3 #qpy:console  import re import sre_constants  PS1 = '>> '  DEFAULT_EVALUATOR = print  class Reple(object):     def __init__(self, evaluator=DEFAULT_EVALUATOR):         self.ps1 = PS1         self.evaluator = evaluator      def read(self):         return input(self.ps1)      def evaluate(self):         return self.evaluator(self.read())      def run(self):         while 1:             try:                 self.evaluate()             except KeyboardInterrupt:                 sys.exit(0)   class REShell(Reple):     def __init__(self, data):         self.data = data         self.ps1 = PS1      def evaluate(self):         try:             expression = re.compile(self.read())             print(*expression.findall(self.data), sep='\n')         except sre_constants.error as error:             print(error)   def source_code():     with open(__file__, 'r') as source:         return source.read()  if __name__ == '__main__':     data = source_code()     print(data)     shell = REShell(data)     shell.run()