Random Choices - Weighting Errors

Question

I am trying to build a lottery system for admissions and the code keeps throwing up the weights error: The code is appended below -

import tkinter as tk
from tkinter import filedialog, messagebox
import pandas as pd
import random

class SchoolAdmissionsApp:
    def __init__(self, root):
        self.root = root
        self.root.title("School Admissions Lottery System")

        self.num_students_label = tk.Label(root, text="Enter number of students to select:")
        self.num_students_label.pack()

        self.num_students_entry = tk.Entry(root)
        self.num_students_entry.pack()

        self.num_students_button = tk.Button(root, text="Set Number of Students", command=self.set_num_students)
        self.num_students_button.pack()

        self.load_button = tk.Button(root, text="Load Excel File", command=self.load_excel_file, state=tk.DISABLED)
        self.load_button.pack()

        self.select_button = tk.Button(root, text="Select Students", command=self.select_students, state=tk.DISABLED)
        self.select_button.pack()

        self.selected_students_window = None
        self.num_students = 0
        self.df = None

    def set_num_students(self):
        try:
            self.num_students = int(self.num_students_entry.get())
            if self.num_students <= 0:
                raise ValueError
            self.load_button.config(state=tk.NORMAL)
            self.select_button.config(state=tk.DISABLED)
            messagebox.showinfo("Number of Students", f"Number of students set to {self.num_students}")
        except ValueError:
            messagebox.showerror("Error", "Please enter a valid number")

    def load_excel_file(self):
        file_path = filedialog.askopenfilename(filetypes=[("Excel files", "*.xlsx")])
        if file_path:
            try:
                self.df = pd.read_excel(file_path)
                self.select_button.config(state=tk.NORMAL)
                messagebox.showinfo("Excel File Loaded", "Excel file loaded successfully")
            except Exception as e:
                messagebox.showerror("Error", f"An error occurred while loading the file:\n{str(e)}")

    def select_students(self):
        if self.num_students == 0 or self.df is None:
            messagebox.showerror("Error", "Please set the number of students and load the Excel file")
            return

        try:
            selected_students = self.process_data(self.df)
            self.display_selected_students(selected_students)
        except Exception as e:
            messagebox.showerror("Error", f"An error occurred:\n{str(e)}")

    def process_data(self, dataframe):
        boys = dataframe[dataframe['Gender'] == 'M']
        girls = dataframe[dataframe['Gender'] == 'F']

        total_students=self.num_students
        boys_count = girls_count = self.num_students // 2

        selected_boys = boys.sample(min(boys_count, len(boys))).reset_index(drop=True)
        selected_girls = girls.sample(min(girls_count, len(girls))).reset_index(drop=True)

        age_dist = [0.25, 0.25, 0.25, 0.25]
        age_range = range(3, 5)

        selected_ages = random.choices(age_range, weights=age_dist, k=self.num_students)

        selected_students = pd.concat([selected_boys, selected_girls], ignore_index=True)
       # selected_students = pd.DataFrame({
            ##'No': selected_boys['No'].tolist() + selected_girls['No'].tolist(),
           ## 'Gender': selected_boys['Gender'].tolist() + selected_girls['Gender'].tolist(),
           ## 'Age': selected_ages

        return selected_students

    def display_selected_students(self, selected_students):
        if self.selected_students_window:
            self.selected_students_window.destroy()

        self.selected_students_window = tk.Toplevel(self.root)
        self.selected_students_window.title("Selected Students")

        text = tk.Text(self.selected_students_window)
        text.pack()

        text.insert(tk.END, selected_students.to_string(index=False))

def main():
    root = tk.Tk()
    app = SchoolAdmissionsApp(root)
    root.mainloop()

if __name__ == "__main__":
    main()

Could someone point out where I am going wrong??

I was expecting the output to contain a equally weighted outcome between M and F and also equally distributed in the quarters of the range of age defined in the code.