擅长:python、mysql、java
<p>请不要多次调用<code>update</code>,例如:</p>
<pre class="lang-py prettyprint-override"><code>>>> import hashlib
>>> mysha1 = hashlib.sha1()
>>> mysha1.update("my_url")
>>> mysha1.hexdigest()
'ebde90b9f0c047ff9f86bec3b71afe5d00594030'
>>> mysha1.hexdigest()
'ebde90b9f0c047ff9f86bec3b71afe5d00594030'
</code></pre>