擅长:python、mysql、java
<p><code>np.hstack()</code>每次都构造一个新的ndarray,这很昂贵。可以使用append就地更新列表:</p>
<pre><code>with open('file.csv') as csvfile:
reader = csv.DictReader(csvfile)
for row in reader:
time.append(row['Time'])
energy.append(row['Energy'])
ondeIG.append(row['OndeIG'])
envelope.append(row['envelope'])
</code></pre>