did birthdays.py

birthdays.py

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+# This program uses a dictionary to keep friends'
+# names and birthdays.
+
+# Global constants for menu choices
+LOOK_UP = 1
+ADD = 2
+CHANGE = 3
+DELETE = 4
+QUIT = 5
+
+# main function
+def main():
+    # Create an empty dictionary.
+    birthdays = {}
+
+    # Initialize a variable for the user's choice.
+    choice = 0
+
+    while choice != QUIT:
+        # Get the user's menu choice.
+        choice = get_menu_choice()
+
+        # Process the choice.
+        if choice == LOOK_UP:
+            look_up(birthdays)
+        elif choice == ADD:
+            add(birthdays)
+        elif choice == CHANGE:
+            change(birthdays)
+        elif choice == DELETE:
+            delete(birthdays)
+
+# The get_menu_choice function displays the menu
+# and gets a validated choice from the user.
+def get_menu_choice():
+    print()
+    print('Friends and Their Birthdays')
+    print('---------------------------')
+    print('1. Look up a birthday')
+    print('2. Add a new birthday')
+    print('3. Change a birthday')
+    print('4. Delete a birthday')
+    print('5. Quit the program')
+    print()
+
+    # Get the user's choice.
+    choice = int(input('Enter your choice: '))
+
+    # Validate the choice.
+    while choice < LOOK_UP or choice > QUIT:
+        choice = int(input('Enter a valid choice: '))
+
+    # return the user's choice.
+    return choice
+
+# The look_up function looks up a name in the
+# birthdays dictionary.
+def look_up(birthdays):
+    # Get a name to look up.
+    name = input('Enter a name: ')
+    # Look it up in the dictionary.
+    print(birthdays.get(name, 'Not found.'))
+
+# The add function adds a new entry into the
+# birthdays dictionary.
+def add(birthdays):
+    # Get a name and birthday.
+    name = input('Enter a name: ')
+    bday = input('Enter a birthday: ')
+
+    # If the name does not exist, add it.
+    if name not in birthdays:
+        birthdays[name] = bday
+    else:
+        print('That entry already exists.')
+
+def change(birthdays):
+    # Get a name to look up.
+    name = input('Enter a name: ')
+    if name in birthdays:
+        # Get a new birthday.
+        bday = input('Enter the new birthday: ')
+        # Update the entry.
+        birthdays[name] = bday
+    else:
+        print('That name is not found.')
+
+# The delete function deletes an entry from the
+# birthdays dictionary.
+def delete(birthdays):
+    # Get a name to look up.
+    name = input('Enter a name: ')
+
+    # If the name is found, delete the entry.
+    if name in birthdays:
+        del birthdays[name]
+    else:
+        print('That name is not found.')
+
+# Call the main function.
+main()