刪除特定文本文件

Question

import os 
folder = 'C:/Python27/Data' 
for the_file in os.listdir(folder): 
    file_path = os.path.join(folder, the_file) 
    try: 
     if os.path.isfile(file_path): 
      os.unlink(file_path) 
    except Exception, e: 
     print e 

這是我用來從目錄中刪除文本文件的代碼，但是我想刪除特定文件，並根據某些關鍵字對它們進行過濾。 如果文本文件不包含單詞「dollar」，則將其從文件夾中刪除。這應該爲目錄內的所有文件完成。

Answer 1

如果文件比較小，那麼下面這個簡單的解決辦法是充分的：

if os.path.isfile(file_path): # or some other condition 
    delete = True    # Standard action: delete 
    try: 
     with open(file_path) as infile: 
      if "dollar" in infile.read(): # don't delete if "dollar" is found 
       delete = False 
    except IOError: 
     print("Could not access file {}".format(file_path)) 
    if delete: 
     os.unlink(file_path) 

如果文件非常大，你不想完全加載它們到內存中（特別是如果你希望在該文件中早期出現的搜索文本），用以下內容替換上述with塊：

 with open(file_path) as infile: 
      for line in file: 
       if "dollar" in line: 
        delete = False 
        break