fix(python): Expose num_non_trivial_top_modules

Recalculate after replacing best tree

Author: danieledler

interfaces/python/infomap.py

@@ -875,6 +875,19 @@ def num_top_modules(self):
         """
         return super().numTopModules()
 
+    @property
+    def num_non_trivial_top_modules(self):
+        """Get the number of non-trivial top modules in the tree
+
+        A trivial module is a module with either one or all nodes within.
+
+        Returns
+        -------
+        int
+            The number of non-trivial top modules
+        """
+        return super().numNonTrivialTopModules()
+
     @property
     def num_leaf_modules(self):
         """Get the number of leaf modules in the tree

src/core/InfomapBase.cpp

@@ -604,6 +604,7 @@ InfomapBase& InfomapBase::initTree(const NodePaths& tree)
 
   aggregateFlowValuesFromLeafToRoot();
   initNetwork();
+  calculateNumNonTrivialTopModules();
 
   m_hierarchicalCodelength = calcCodelengthOnTree(true);
   Log() << "\n -> Initiated to codelength " << m_hierarchicalCodelength << " in " << maxDepth << " levels with " << numTopModules() << " top modules." << std::endl;