>>> s='RETEZEC'
>>> s.join(['ahoj','nazdar','cau'])
'ahojRETEZECnazdarRETEZECcau'
>>> s.join('abcd')
'aRETEZECbRETEZECcRETEZECd'
>>> ':'.join(['ahoj','nazdar','cau'])
'ahoj:nazdar:cau'
>>> 
