擅长:python、mysql、java
<p>我不知道为什么<code>IndexedBase</code>方法不起作用(我也很想知道)。但是,您可以执行以下操作:</p>
<pre><code>import sympy as sp
numSpecies = 10
n = sp.symbols('n0:%d'%numSpecies) # note that n equals the tuple (n0, n1, ..., n9)
ntot = sum(n) # sum elements of n using the standard
# Python function for summing tuple elements
#ntot = sp.Add(*n) # same result using Sympy function
sp.diff(ntot, n[5])
</code></pre>