两种方法：

1. print附加end=

2. join方法

s = [['a','1','.'],['T','o','o','m']]
# -----------two line-------------
for i in range(len(s)):for j in range(len(s[i])):print(s[i][j], end='')print()
for i in range(len(s)):print(''.join(s[i]))
# -----------one line-------------
for i in range(len(s)):for j in range(len(s[i])):print(s[i][j], end='')
print()
ot = []
for i in range(len(s)):ot = ot+s[i]
print(''.join(ot))

result：
a1.
Toom
a1.
Toom
a1.Toom
a1.Toom