擅长:python、mysql、java
<p>您可以按照<a href="https://docs.python.org/2/glossary.html#term-eafp" rel="noreferrer">^{<cd1>} principle</a>和<a href="https://stackoverflow.com/questions/12265451/ask-forgiveness-not-permission-explain">ask for forgiveness</a>:</p>
<pre><code>import pickle
try:
foo = pickle.load(open("var.pickle", "rb"))
except (OSError, IOError) as e:
foo = 3
pickle.dump(foo, open("var.pickle", "wb"))
</code></pre>