python缩进可以用tab吗

def perm(l):#0

        # Compute the list of all permutations of l

    if len(l) <= 1:# 1

                  return [l]# 2

    r = []# 3

    for i in range(len(l)):# 4

             s = l[:i] + l[i+1:]# 5

             p = perm(s)# 6

             for x in p:# 7

              r.append(l[i:i+1] + x)# 8

    return r# 9

def perm(l):                       #1 error: first line indented

    for i in range(len(l)):             #2 error: not indented

        s = l[:i] + l[i+1:]

            p = perm(l[:i] + l[i+1:])   #3 error: unexpected indent

            for x in p:

                    r.append(l[i:i+1] + x)#4

                return r                #5 error: inconsistent dedent