title: How to count products per each category and sub-category?
body: <p>According to the specified dataframe</p>
  <pre><code>category_uuid   collection_uuid product_uuid
  fe4eef35-3fde-4037-a6ce-e8ebd2859cd6    0020005c-55e3-47cb-9056-ed25dd5f24f0    00a1c641-2f8f-440d-b105-d89180cac625
  fe4eef35-3fde-4037-a6ce-e8ebd2859cd6    0020005c-55e3-47cb-9056-ed25dd5f24f0    021bb4b1-e21e-4ba5-8856-15198585f873
  fe4eef35-3fde-4037-a6ce-e8ebd2859cd6    0020005c-55e3-47cb-9056-ed25dd5f24f0    0331a74f-1e99-418e-9abc-304d269452b2
  
  </code></pre>
  <p>I need to calculate the following aggregated values:</p>
  <pre><code>category_uuid   collections_count   products_count
  fe4eef35-3fde-4037-a6ce-e8ebd2859cd6    124 1563
  ...
  </code></pre>
  <p>i.e. to aggregate the total number of products and collections for each category.</p>
  <p>I've tried to do the following:</p>
  <pre><code>df_products_small.groupby(['category_uuid']).agg({'collection_uuid': ['count'], ' products_count': ['count'] })
  </code></pre>