fp = file('data.txt')
lines = []
for line in fp:
lines.append(line)
fp.close()
lines.insert(1, 'a new line') # 在第二行插入
s = '\n'.join(lines)
fp = file('data.txt', 'w')
fp.write(s)
fp.close()
fp = file('data.txt')
lines = []
for line in fp:
lines.append(line)
fp.close()
lines.insert(1, 'a new line') # 在第二行插入
s = '\n'.join(lines)
fp = file('data.txt', 'w')
fp.write(s)
fp.close()