str.partition(sep)
Split the string at the first occurrence of sep, and return a 3-tuple containing the part before the separator, the separator itself, and the part after the separator.
If the separator is not found, return a 3-tuple containing the string itself, followed by two empty strings.
>>> s = "34;45;98;3"
>>> s.partition(";")
('34', ';', '45;98;3')
>>>
>>> # compare with
...
>>> s.split(";",1)
['34', '45;98;3']