new_contents: import unittest
  import sys
  sys.path.append('../') # path to source file (ownfunctions.py)
  
  import ownfunctions  
  
  class TestZeichenErsetzen(unittest.TestCase):
  
      def test_hallo(self):
          x = ownfunctions.zeichen_ersetzen("hallo")
          self.assertEqual(x,"hallo")
          
      def test_maerchen(self):
          x = ownfunctions.zeichen_ersetzen(u"m{}rchen".format(u"\u00E4"))
          self.assertEqual(x, u"m{}rchen".format(u"\u00E4"))
          
      def test_hyphen_u2013(self):
          x = ownfunctions.zeichen_ersetzen(u"hey {} was geht?".format(u"\u2013"))
          self.assertEqual(x, u"hey - was geht?")
          
      def test_smiley_u263a(self):
          x = ownfunctions.zeichen_ersetzen(u"hallo {}".format(u"\u263a"))
          self.assertEqual(x, u"hallo :-)")
      
      def test_sum_u2211(self):
          x = ownfunctions.zeichen_ersetzen(u"{}(1,2,3,4)".format(u"\u2211"))
          self.assertEqual(x, u"sum(1,2,3,4)")
          
      def test_squareroot_u221a(self):
          x = ownfunctions.zeichen_ersetzen(u"{}(4) = 2".format(u"\u221a"))
          self.assertEqual(x, u"sqrt(4) = 2")
  
  if __name__ == '__main__':
      suite = unittest.TestLoader().loadTestsFromTestCase(TestZeichenErsetzen)
      unittest.TextTestRunner(verbosity=2).run(suite)
subject: add tests for ownfunctions.zeichen_ersetzen