刪除兩個文件中的罕見行，但保留文件結構

Question

我有兩個文件，我想保留文件1的結構（使行保留「>」），刪除文件1和文件2中的非常見行。示例：

文件1：

>countries 
France 
Italy 
>cities 
Rome 

文件2：

France 

希望的輸出（消除罕見線，保持爲 「>」 行）：

>countries 
France 
>cities 

任何想法？

Answer 1

試試這個

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") 

Answer 2

我會加載你想保留在列表中的國家，以及你在列表中經歷的文件。如果該行中有>字符，請將其附加到新的輸出列表中，或者該行在File 2中，然後將其附加到輸出列表中。然後遍歷輸出列表中的每個項目並將其寫入輸出文件。

with open("test.txt", "r") as file1: 
    file1Lines = file1.readlines() 
with open("test2.txt", "r") as file2: 
    countriesToKeep = file2.readlines() 

newFileLines = [] 
for line in file1Lines: 
    if ">" in line: 
     newFileLines.append(line) 
    elif line.strip() in countriesToKeep: 
     newFileLines.append(line) 

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

Answer 3

也許這樣嗎？

我的方法是從第二個文件創建一個要保留的行的列表。該列表包含該文件中不以>開頭的行（不確定是否允許第二個文件包含>）。然後遍歷第一個文件，並只採用以>開頭的行或來自Keepers列表的行。

with open('file1.txt') as f1, open('file2.txt') as f2: 

    keepers = {line.strip() for line in f2 if not line.startswith('>')} 

    lines = [line.strip() for line in f1] 

    with open('out.txt', 'w') as fout: 
     for line in lines: 
      if line.startswith('>'): 
       fout.write(line + '\n') 
      elif line in keepers: 
       fout.write(' ' + line + '\n') 

Answer 4

一行代碼版本：

print '\n'.join(filter(lambda x: x.startswith('>') or x in map(lambda x: x.strip(), open('file2.txt').readlines()), map(lambda x: x.strip(), open('file1.txt').readlines())))