Handle ValueError.

.gitignore

@@ -112,3 +112,4 @@ dmypy.json
 
 # database files (may contain sensitive student info)
 *.db
+.vscode

TODO.md

@@ -2,7 +2,7 @@ To-Do List
 ==========
 
 ## v0.2
-- [ ] Error handling (when entering invalid data types)
+- [x] Error handling (when entering invalid data types)
 - [ ] Make database contain data for all classes
 - [ ] Flexible mandatory subjects
 

ib-clearance.py

@@ -102,6 +102,7 @@ def main():
 
     y = "y"
     while y == "y":
+        try:
             id = int(input("Please input the student ID number: "))
 
             if check_id(conn, id):
@@ -119,6 +120,8 @@ def main():
                     print("Clear to leave.")
             else:
                 print("Student does not exist in the database. Please try again.")
+        except ValueError:
+            print("That was not an integer, please try again.")
 
         y = input("Press y key followed by enter to run again.")