"Friend group data model" stretch and self-done exercises

group.py

@@ -1,5 +1,76 @@
 """An example of how to represent a group of acquaintances in Python."""
 
-# Your code to go here...
+class Person:
 
-my_group =
+	def __init__(self, name, age, job=None):
+		self.name = name
+		self.job = job
+		self.age = age
+		self.relationships = []
+
+	def __str__(self):
+		out_start = f"{self.name} is {self.age}"
+		# optional parameter: job
+		if not self.job:
+			out_job = ""
+		elif self.job[0].lower() in ["a","e","i","o"]:
+			out_job = f", an {self.job}"
+		else:
+			out_job = f", a {self.job}"
+		# optional parameter: relationship
+		rel_str_list = [f"{self.relationships[i][1]}'s {self.relationships[i][0]}" for i in range(len(self.relationships))]
+		if not rel_str_list:
+			out_relationship = ""
+		elif len(rel_str_list) > 2:
+			out_relationship = "; they are " + ", ".join(rel_str_list[:-2]) + ", " + " and ".join(rel_str_list[-2:])
+		else:
+			out_relationship = "; they are " + " and ".join(rel_str_list)
+		return out_start + out_job + out_relationship
+
+	def add_relationship(self, rel_type, person):
+		if type(rel_type) in [list, tuple]:
+			self.relationships.append((rel_type[0], person.name))
+			person.relationships.append((rel_type[1], self.name))
+		else:
+			self.relationships.append((rel_type, person.name))
+			person.relationships.append((rel_type, self.name))
+
+	def forget_relationship(self, person):
+		for i, relationship in enumerate(self.relationships):
+			if relationship[1] == person.name:
+				del self.relationships[i]
+		for i, relationship in enumerate(person.relationships):
+			if relationship[1] == self.name:
+				del person.relationships[i]
+
+def add_person(group, person):
+	group += person
+
+def average_age(group):
+	ages = []
+	for i in group:
+		ages.append(i.age)
+	return sum(ages)/len(ages)
+
+my_group = []
+jill = Person("Jill", 26, "Biologist")
+zalika = Person("Zalika", 28, "Artist")
+john = Person("John", 27, "Writer")
+nash = Person("Nash", 34, "Chef")
+
+add_person(my_group, [jill, zalika, john, nash])
+
+jill.add_relationship("Friend", zalika)
+jill.add_relationship("Partner", john)
+nash.add_relationship("Cousin", john)
+nash.add_relationship(("Landlord", "Tenant"), zalika)
+
+print("\n".join([str(my_group[i]) for i in range(len(my_group))]))
+print("The average age of people in the group is", average_age(my_group))
+
+# Exercises
+print("The maximum age of people in the group is", max([i.age for i in my_group]))
+len_relationships = [len(i.relationships) for i in my_group]
+print("The average (mean) number of relations among members of the group is", sum(len_relationships)/len(len_relationships))
+print("The maximum age of people in the group that have at least one relation is", max([i.age for i in my_group if len(i.relationships) >= 2]))
+print("The maximum age of people in the group that have at least one friend is", max([i.age for i in my_group if len([j[1] for j in i.relationships if j[0] == "Friend"]) >= 1]))