检查对象是否为None的最佳方法是？

Question

我该如何解决此错误？似乎是此存储库中未解决的问题：https://github.com/shayanzare007/EntitySentiment/issues/7

$ python RunRNN.py 
Number of unique words: 9869
Opening the file...
File successfully read
Opening the file...
File successfully read
Opening the file...
File successfully read
Number of training samples 5003
Traceback (most recent call last):
  File "RunRNN.py", line 84, in <module>
    curve = model.train_sgd(X,Y,idxiter_random,None,400,400) 
  File "/scratch2/debate_tweets/sentiment/EntitySentiment/nn/base.py", line 386, in train_sgd
    if idxiter == None: # default training schedule
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Answer 1

在测试对象的无效性时，建议的做法是始终使用is：

if idxiter is None:
    ...

它更安全，特别是因为并非所有对象都支持与None进行平等比较。