Object-oriented structure UCL-RITS#168

week09/refactoring/initial_two_classes.py

@@ -18,7 +18,7 @@ def __init__(self):
 
     def size(self):
         """Return how many people are in the group."""
-        pass
+        return len(self.members)
 
     def contains(self, name):
         """Check whether the group contains a person with the given name.
@@ -28,21 +28,49 @@ def contains(self, name):
 
     def add_person(self, name, age, job):
         """Add a new person with the given characteristics to the group."""
+        if self.contains(name):
+            raise ValueError(f"I already know about {name}.")
         self.members.append(Person(name, age, job))
 
     def number_of_connections(self, name):
         """Find the number of connections that a person in the group has"""
-        pass
+        # Raise an error if the specified person is not in the group
+        if not self.contains(name):
+            raise ValueError(f"I don't know about {name}.")
+        num_of_con = 0
+        for first_person, second_person in self.connections:
+            if first_person == name:
+                num_of_con = num_of_con+1
+        return num_of_con
 
     def connect(self, name1, name2, relation, reciprocal=True):
         """Connect two given people in a particular way.
         Optional reciprocal: If true, will add the relationship from name2 to name 1 as well
         """
-        pass
+        if not self.contains(name1):
+            raise ValueError(f"I don't know who {name1} is.")
+        if not self.contains(name2):
+            raise ValueError(f"I don't know who {name2} is.")
+        if (name1, name2) in self.connections:
+            raise ValueError(f"{name1} already knows {name2} as a "
+                             f"{self.connections[(name1, name2)]}")
+        # The part below is for when the reciprocal relation is needed.
+        self.connections[(name1, name2)] = relation
+        if reciprocal:
+            self.connections[(name2, name1)] = relation
+
 
     def forget(self, name1, name2):
         """Remove the connection between two people."""
-        pass
+        # Raise errors
+        if not self.contains(name1):
+            raise ValueError(f"I don't know who {name1} is.")
+        if not self.contains(name2):
+            raise ValueError(f"I don't know who {name2} is.")
+        if (name1, name2) not in self.connections:
+            raise ValueError(f"{name1} does not know {name2} yet.")
+        # If pass, remove it
+        self.connections.pop((name1, name2))
 
     def average_age(self):
         """Compute the average age of the group's members."""
@@ -55,8 +83,16 @@ def average_age(self):
     my_group = Group()
     # ...then add the group members one by one...
     my_group.add_person("Jill", 26, "biologist")
+    my_group.add_person("Zalika", 28, "artist")
+    my_group.add_person("John", 27, "writer")
+    my_group.add_person("Nash", 34, "chef")
+
     # ...then their connections
     my_group.connect("Jill", "Zalika", "friend")
+    my_group.connect("Jill", "John", "partner")
+    my_group.connect("Nash", "John", "cousin", reciprocal=False)
+    my_group.connect("Nash", "Zalika", "landlord", reciprocal=False)
+
     # ... then forget Nash and John's connection
     my_group.forget("Nash", "John")