如何在python中从文件中连续写两行？

Question

old = open('./old.txt')
new = open('./new.txt','w')
for line in file:
    if '22%' in line:
        new.write(line)
new.close()

上面的代码将包含22％的行写入新文件。应该进行哪些更改以编写紧跟在包含22％的行之后的行？

例如： old.txt有

abc

def

g22%hi

jkl

mno

new.txt应该有

g22%hi

jkl

Answer 1

您可以使用标记或使用其他人在评论中说的next：

some_flag = False
for line in file:
    if some_flag:
        new.write(line)
        some_flag = False
    if '22%' in line:
        new.write(line)
        some_flag = True

new.close()

Answer 2

您可以对现有代码进行最简单的更改，并解决问题：

old = open('./old.txt')
new = open('./new.txt','w')
prevLine = ""
for line in file:
    if '22%' in line or '22%' in prevLine:
        prevLine = line
        new.write(line)
new.close()