text: x = "zer"
  assert x.capitalize() == "Zer"
  assert str.capitalize(x) == "Zer"
  
  x = "azert$t y t"
  assert x.count('t')==3
  assert str.count(x,'t')==3
  
  assert x.endswith("y t")==True
  
  assert x.find('t')==4
  assert x.find('$')==5
  assert x.find('p')==-1
  
  assert x.index('t')==4
  
  items = ['sd','kj']
  assert '-'.join(items)=="sd-kj"
  
  assert "ZER".lower()=="zer"
  
  assert "azerty".lstrip('a')=="zerty"
  assert "azerty".lstrip('za')=="erty"
  assert "azaerty".lstrip('az')=="erty"
  
  assert "$XE$".replace("$XE$", "!")=="!"
  assert "$XE".replace("$XE", "!")=='!'
  assert "XE$".replace("XE$", "!")=="!"
  assert "XE$".replace("$", "!")=="XE!"
  assert "$XE".replace("$", "!")=="!XE"
  assert "?XE".replace("?", "!")=="!XE"
  assert "XE?".replace("?", "!")=="XE!"
  assert "XE!".replace("!", "?")=="XE?"
  
  assert "azterty".find('t')==2
  assert "azterty".rfind('t')==5
  assert "azterty".rfind('p')==-1
  
  assert "azterty".rindex('t')==5
  
  try:
      "azterty".rindex('p')
  except ValueError:
      pass
  
  assert "azerty".rstrip('y')=="azert"
  assert "azerty".rstrip('yt')=="azer"
  assert "azeryty".rstrip('ty')=="azer"
  
  assert "az er ty".split()==["az","er","ty"]
  assert "azferfty".split('f')==["az","er","ty"]
  assert "az\ner\nty".splitlines()==["az","er","ty"]
  
  assert "azerty".startswith('az')
  
  assert "  azerty ".strip() == "azerty"
  
  assert "bghggbazertyhbg".strip("bhg") == "azerty"
  
  assert "zer".upper() == "ZER"
  
  print("passed all tests...")
  