请教一个关于正则表达式的问题

Question

请问，如何用正则表达式将列表中的邮箱信息提取出？如下：

l1=['a', 'b', 'c', 'd', 'E-Mail：[e-mail]', e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u]
l2=[1,2,3,4, '[e-mail]', 5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
l3=['a', 'b', 'c', 'd', '邮箱：123@gmail', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm']
l4=[a,b,c,d,5,6,7,8,9,10,11,12,h,i,j,k,l,m,n,o,p]

如何将列表中的邮箱提出，得到['[e-mail]','[e-mail]',123@gmail',None]的列表

Answer 1

def getmail(l_str):
    str_mail = []
    for i in l_str:
        if isinstance(i, str):
            nPos = i.find('@')
            if nPos > 0:           
                fon = ""
                pos = i[nPos : len(i)]
                for j in range(nPos - 1, 0, -1):
                    if i[j].isdigit() or i[j].isalpha():
                        fon = i[j] + fon
                    else:
                        break
                cur_email = fon + pos
                str_mail.append(cur_email)
    if len(str_mail) == 0:
        str_mail.append("None")
    return str_mail

l1=['a', 'b', 'c', 'd', 'E-Mail：[e-mail]','e','f','g','h','i','j']
l2=[1,2,3,4, '[e-mail]', 5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
l3=['a', 'b', 'c', 'd', '邮箱：123@gmail', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm']
l4=['a', 'b', 'c', 'd',5,6,7,8,9,10,11,12,'h', 'i', 'j', 'k', 'l', 'm']


mails = [];
mails.append(getmail(l1)[0])
mails.append(getmail(l2)[0])
mails.append(getmail(l3)[0])
mails.append(getmail(l4)[0])

print mails