擅长:python、mysql、java
<p>要访问字典中的键:</p>
<pre><code>mydict={'mykey':['value1','value2']}
#access mykey from mydict:
mydict['mykey']
</code></pre>
<p>要将这些数据正确地加载到dict中,我可以这样做:</p>
<pre><code>def unpickle(file):
import pickle
dict={}
with open(file, 'rb') as fo:
dict[fo] = pickle.load(fo, encoding='bytes')
return dict
#how to access the data in your train[j] dict:
[v for v in train[j].values()]
</code></pre>
<p>python等效于获取矩阵的前两行:</p>
<pre><code>A=np.matrix([[1, 2, 3], [3, 4, 5], [5, 6, 7]])
A[:,[0,1]]
</code></pre>
<p>请记住,对于python,索引从0开始。matlab索引从1开始。你知道吗</p>