om</span> <span class="nn">abc</span> <span class="kn">import</span> <span class="n">ABC</span><span class="p">,</span> <span class="n">abstractmethod</span>

<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>

<span class="kn">import</span> <span class="nn">sparse</span> <span class="k">as</span> <span class="nn">sp</span>

<span class="kn">from</span> <span class="nn">dscribe.utils.species</span> <span class="kn">import</span> <span class="n">