initial commit

__main__.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3.11
+from customtkinter import set_appearance_mode, set_default_color_theme
+from customtkinter import CTk, CTkEntry, CTkButton, CTkLabel, CTkFrame
+
+class Window:
+	def __init__(self):
+		self.amountDue: float = 0.0
+		
+		set_appearance_mode("dark")
+		set_default_color_theme("dark-blue")
+
+		self.root = CTk()
+		self.root.geometry("720x480")
+
+		self.frame = CTkFrame(master=self.root)
+		self.frame.pack(pady=20, padx=60, fill="both", expand=True)
+
+		# Static label
+		_mainLabel: CTkLabel = CTkLabel(master=self.frame, text="Change Due Calculator")
+		_mainLabel.pack(pady=12, padx=10)
+
+		self.entry: CTkEntry = CTkEntry(master=self.frame, placeholder_text="Amount Charged...")
+		self.entry.pack(pady=12, padx=10)
+
+		self.invalidLabel = CTkLabel(master=self.frame, text="Not a number", text_color="red")
+
+		calculateButton: CTkButton = CTkButton(master=self.frame, text="Calculate", command=self.calculate)
+		calculateButton.pack(pady=12, padx=10)
+
+		self.root.mainloop()
+
+	def _validateInput(func: callable) -> callable:
+		def wrapper(self):
+			self.invalidLabel.pack_forget()
+			try:
+				self.amountDue = float(self.entry.get())
+			except ValueError:
+				self.invalidLabel.pack()
+				return
+			func(self)
+
+		return wrapper
+
+	@_validateInput
+	def calculate(self) -> None:
+		print(self.amountDue)
+
+if __name__ == '__main__':
+	window = Window()