str.join(list/tuple/dict/string)
str = "-"; seq = ("a", "b", "c"); # 字符串序列 print(str.join( seq ));
#结果:a-b-c
list=['1','2','3','4','5']
print(''.join(list))
#结果:12345
seq = {'hello':'nihao','good':2,'boy':3,'doiido':4}
print('-'.join(seq)) #字典只对键进行连接
#结果:hello-good-boy-doiido