删除两个文件中不常见的行，但保留文件结构

Question

我有两个文件，我想保留文件1的结构（保留带“>；”的行），删除文件1和文件2中不常见的行。示例：

文件1：

>countries
 France
 Italy
>cities
 Rome

文件2：

France

所需输出（删除不常用行，保留“>；”行）：

>countries
 France 
>cities

有什么想法吗？你知道吗

Answer 1

试试这个

with open("f1.txt") as file1:
    file1Lines = file1.readlines()
with open("f2.txt") as file2:
    countriesToKeep = file2.readlines()
file1Lines = [i.strip() for i in file1Lines]
countriesToKeep = [i.strip() for i in countriesToKeep]
newFileLines = []
for line in file1Lines:
    if line.startswith(">"):
        newFileLines.append(line)
    elif line in countriesToKeep:
        newFileLines.append(" "+line)

with open("output.txt", "w") as output:
    for line in newFileLines:
        output.write(line+"\n")