擅长:python、mysql、java
<p>从<a href="https://docs.scipy.org/doc/numpy-1.15.1/reference/generated/numpy.random.randint.html" rel="nofollow noreferrer">the documentation</a>:</p>
<blockquote>
<p>dtype : dtype, optional</p>
<p>Desired dtype of the result. All dtypes are determined by their name, i.e., ‘int64’, ‘int’, etc, so byteorder is not available and a specific precision may have different C types depending on the platform. The default value is ‘np.int’.</p>
<p>New in version 1.11.0.</p>
</blockquote>
<p>(<code>dtype</code>是<code>data type</code>的缩写,是大量Numpy函数的参数。)</p>
<p>除非您另外指定,<code>np.random.randint</code>将为您提供<code>np.int</code>大小的值,这些值将占用四个字节的空间。(对于指定的随机范围,单字节是否足够并不重要。)</p>
<p>要解决此问题,请指定<a href="https://docs.scipy.org/doc/numpy/user/basics.types.html" rel="nofollow noreferrer">appropriate</a>数据类型:</p>
<pre><code>a = np.random.randint(0, 255, size=(20,20), dtype=np.uint8)
</code></pre>