Merge branch 'patch-4' into 'master'

Update family_tree.py

See merge request !4

family_tree.py

@@ -217,7 +217,7 @@ class FamilyTree:
         """Return the index in the times table."""
         return self.times[n]
 
-    def great(self, n):
+    def GREAT(self, n):
         """Return a string of n 'greats' separated by '-' ."""
         return "-".join(["great"]*n)
 
@@ -433,7 +433,7 @@ def commandLine():
 				print("Error: no such person " + cmd[1])
 		elif cmd[0] == "edit-age":
 			try:
-				tree.get_person(cmd[1]).set_name(cmd[2])
+				tree.get_person(cmd[1]).set_age(cmd[2])
 			except KeyError:
 				print("Error: no such person " + cmd[1])
 		elif cmd[0] == "edit-sex":
@@ -446,13 +446,21 @@ def commandLine():
 				print("Error: no such person " + cmd[1])
 		elif cmd[0] == "relationship":
 			try:
+			    if cmd[1] == cmd[2]:
+			        print("Error: inputs must be distinct")
+			    else:
 				    print(tree.relationship(tree.get_person(cmd[1]), tree.get_person(cmd[2])))
 			except KeyError:
 				print("Error: one or both persons do not exist")
 		elif cmd[0] == "load":
+		    try:
 			    tree = openfile(cmd[1])
 			    print(cmd[1] + ".ft has been loaded")
+			except FileNotFoundError:
+			     print("Error: File not found")   
 		elif cmd[0] == "save":
+		    tree.find_root()
+		    tree.precompute()
 			savefile(cmd[1], tree)
 			print("file saved")
 		elif cmd[0] == "bye":