list转str

a = [(1411679,), (1552040,), (1434239,)]  #给出的列表
b = [i[0] for i in a]   #取出想要的值
print(b)
>>>>>>>[1411679, 1552040, 1434239]  #b的值
c = list(map(str, b))  #为了后面把list中的元素整体转为str
print(c)
>>>>>>>['1411679', '1552040', '1434239']  #c的值
d = ','.join(c)
print(d)
>>>>>>>1411679,1552040,1434239  #d的值，类型为str