In the code below,
try: accommodation_budget = float(self.accommodation_expense_entry.get()) transport_budget = float(self.transport_expense_entry.get()) meals_budget = float(self.meals_expense_entry.get()) activities_budget = float(self.activities_expense_entry.get()) except ValueError: self.itinerary_text.insert(tk.END, "The expenses are not expected to be written in the another format.\n") return
the program attempts to convert user inputs from GUI entry fields into floating-point numbers. This is necessary for performing budget calculations. However, users might accidentally input non-numeric values—such as letters, symbols, or leave the fields blank—which would cause a ValueError when using float(). By wrapping these conversions in a try/except block: the program avoids crashing when invalid input is entered; it provides a clear, user-friendly error message indicating that the input format is incorrect and it allows the program to fail gracefully and continue running instead of terminating unexpectedly. Without this block, the app would raise an unexpected exception and no budget can be calculated.