diff --git a/data_structures/trie/radix_tree.py b/data_structures/trie/radix_tree.py
index caf566a6c..34aa5f01c 100644
--- a/data_structures/trie/radix_tree.py
+++ b/data_structures/trie/radix_tree.py
@@ -62,12 +62,17 @@ class RadixNode:
         -- A   (leaf)
         --- A   (leaf)
         """
-        # Case 1: If the word is the prefix of the node
+        # Case 1: If the word is empty, mark current node as leaf
+        if not word:
+            self.is_leaf = True
+            return
+
+        # Case 2: If the word is the prefix of the node
         # Solution: We set the current node as leaf
         if self.prefix == word and not self.is_leaf:
             self.is_leaf = True
 
-        # Case 2: The node has no edges that have a prefix to the word
+        # Case 3: The node has no edges that have a prefix to the word
         # Solution: We create an edge from the current node to a new one
         # containing the word
         elif word[0] not in self.nodes:
@@ -79,12 +84,12 @@ class RadixNode:
                 word
             )
 
-            # Case 3: The node prefix is equal to the matching
+            # Case 4: The node prefix is equal to the matching
             # Solution: We insert remaining word on the next node
             if remaining_prefix == "":
-                self.nodes[matching_string[0]].insert(remaining_word)
+                incoming_node.insert(remaining_word)
 
-            # Case 4: The word is greater equal to the matching
+            # Case 5: The word is greater equal to the matching
             # Solution: Create a node in between both nodes, change
             # prefixes and add the new node for the remaining word
             else:
diff --git a/greedy_methods/fractional_knapsack.py b/greedy_methods/fractional_knapsack.py
index d52b56f23..f7455a9c9 100644
--- a/greedy_methods/fractional_knapsack.py
+++ b/greedy_methods/fractional_knapsack.py
@@ -39,9 +39,11 @@ def frac_knapsack(vl, wt, w, n):
     return (
         0
         if k == 0
-        else sum(vl[:k]) + (w - acc[k - 1]) * (vl[k]) / (wt[k])
-        if k != n
-        else sum(vl[:k])
+        else (
+            sum(vl[:k]) + (w - acc[k - 1]) * (vl[k]) / (wt[k])
+            if k != n
+            else sum(vl[:k])
+        )
     )
 
 
diff --git a/matrix/matrix_class.py b/matrix/matrix_class.py
index a5940a38e..230eb9500 100644
--- a/matrix/matrix_class.py
+++ b/matrix/matrix_class.py
@@ -204,9 +204,11 @@ class Matrix:
         return Matrix(
             [
                 [
-                    self.minors().rows[row][column]
-                    if (row + column) % 2 == 0
-                    else self.minors().rows[row][column] * -1
+                    (
+                        self.minors().rows[row][column]
+                        if (row + column) % 2 == 0
+                        else self.minors().rows[row][column] * -1
+                    )
                     for column in range(self.minors().num_columns)
                 ]
                 for row in range(self.minors().num_rows)