python组合问题有一个二维数列list=[['a','b'],['c','d','e'],'f',['g','h',

a = [['a','b'],['c','d','e'],'f',['g','h','i','j']]
for i in range(len(a)):
if isinstance(a[i],str):
a[i] = [a[i]]

anum = [len(i) for i in a]
x = []
for i in range(int(''.join(map(str,anum)))):
for j in zip(list(str(i).zfill(len(a))),anum):
if int(j[0]) >= j[1]:
break
else:
x.append(list(map(int,list(str(i).zfill(len(anum))))))
temp = []
c = []
for i in x:
temp.clear()
for j,k in enumerate(i):
temp.append(a[j][k])
else:
c.append(temp)
print(c)