simplified the code following reviews

Author: manueldilullo

graphs/random_graph_generator.py

@@ -6,7 +6,7 @@
 URL: https://en.wikipedia.org/wiki/Random_graph
 """
 
-import numpy as np
+import random
 
 
 def random_graph(
@@ -16,33 +16,33 @@ def random_graph(
     Function that generates a random graph
     @input: vertices_number (number of vertices),
             probability (probability that a generic edge (u,v) exists),
-            directed (if True: g will be a directed graph,
+            directed (if True: graph will be a directed graph,
                       otherwise it will be an undirected graph)
     @examples:
     >>> random_graph(4, 1)
     {0: [1, 2, 3], 1: [0, 2, 3], 2: [0, 1, 3], 3: [0, 1, 2]}
     >>> random_graph(4, 1, True)
     {0: [1, 2, 3], 1: [0, 2, 3], 2: [0, 1, 3], 3: [0, 1, 2]}
     """
-    g = dict(zip(range(vertices_number), [[] for _ in range(vertices_number)]))
+    graph = {i: [] for i in range(vertices_number)}
 
     # if probability is greater or equal than 1, then generate a complete graph
     if probability >= 1:
         return complete_graph(vertices_number)
     # if probability is lower or equal than 0, then return a graph without edges
     if probability <= 0:
-        return g
+        return graph
 
     # for each couple of nodes, add an edge from u to v
     # if the number randomly generated is greater than probability probability
     for i in range(vertices_number):
         for j in range(i + 1, vertices_number):
-            if np.random.random() < probability:
-                g[i].append(j)
+            if random.random() < probability:
+                graph[i].append(j)
                 if not directed:
                     # if the graph is undirected, add an edge in from j to i, either
-                    g[j].append(i)
-    return g
+                    graph[j].append(i)
+    return graph
 
 
 def complete_graph(vertices_number: int) -> dict:
@@ -54,13 +54,9 @@ def complete_graph(vertices_number: int) -> dict:
     >>> print(complete_graph(3))
     {0: [1, 2], 1: [0, 2], 2: [0, 1]}
     """
-    g = {}
-    for i in range(vertices_number):
-        g[i] = []
-        for j in range(0, vertices_number):
-            if i != j:
-                g[i].append(j)
-    return g
+    return {
+        i: [j for j in range(vertices_number) if i != j] for i in range(vertices_number)
+    }
 
 
 if __name__ == "__main__":