跨平臺的/ dev/Python中的空

Question

我使用下面的代碼隱藏一個Python庫我不控制在Linux/OSX標準錯誤默認情況下，寫至標準錯誤：

f = open("/dev/null","w") 
zookeeper.set_log_stream(f) 

是否有輕鬆跨平臺替代/ dev/null？理想情況下，它不會消耗內存，因爲這是一個漫長的過程。

Answer 1

os.devnull怎麼樣？

import os 
f = open(os.devnull,"w") 
zookeeper.set_log_stream(f) 

Answer 2

>>> import os 
>>> os.devnull 
'nul' 

Answer 3

class Devnull(object): 
    def write(self, *_): pass 

zookeeper.set_log_stream(Devnull()) 

開放os.devnull是太細當然，但是這種方式產生的每個輸出操作（作爲一個空操作）「處理中」 - 沒有上下文切換到OS和背面，並且還沒有緩衝（而一些緩衝通常由open使用），因此更少的內存消耗。

Answer 4

創建你自己的文件類對象，它什麼都不做？

class FakeSink(object): 
    def write(self, *args): 
     pass 
    def writelines(self, *args): 
     pass 
    def close(self, *args): 
     pass 

Answer 5

便宜的解決方案警告！

class DevNull(): 
    def __init__(self, *args): 
    self.closed = False 
    self.mode = "w" 
    self.name = "<null>" 
    self.encoding = None 
    self.errors = None 
    self.newlines = None 
    self.softspace = 0 
    def close(self): 
    self.closed == True 
    @open_files_only 
    def flush(self): 
    pass 
    @open_files_only 
    def next(self): 
    raise IOError("Invalid operation") 
    @open_files_only 
    def read(size = 0): 
    raise IOError("Invalid operation") 
    @open_files_only 
    def readline(self): 
    raise IOError("Invalid operation") 
    @open_files_only 
    def readlines(self): 
    raise IOError("Invalid operation") 
    @open_files_only 
    def xreadlines(self): 
    raise IOError("Invalid operation") 
    @open_files_only 
    def seek(self): 
    raise IOError("Invalid operation") 
    @open_files_only 
    def tell(self): 
    return 0 
    @open_files_only 
    def truncate(self): 
    pass 
    @open_files_only 
    def write(self): 
    pass 
    @open_files_only 
    def writelines(self): 
    pass 

def open_files_only(fun): 
    def wrapper(self, *args): 
    if self.closed: 
     raise IOError("File is closed") 
    else: 
     fun(self, *args) 
    return wrapper