python字符串
s1="...a..b..c..."
s1.split(".")#['', '', '', 'a', '', 'b', '', 'c', '', '', '']
s1 = "abccabcbaaabba"
s1.strip("ab")#'ccabc'
s1="...a..b..c..."
s1.split(".")#['', '', '', 'a', '', 'b', '', 'c', '', '', '']
s1 = "abccabcbaaabba"
s1.strip("ab")#'ccabc'