Ok so quick answer to fix the main problem is to add a new argument to all functions in calculadora.py lets call this argument window because we are passing the the root window to each function.

Then you need to build the root window as a class with class attributes. This way your functions in calculadora can actually update the the fields.

Once we changed those 2 parts we need to pass that window to those functions from the frame_botoes.py buttons so we will update those buttons as well.

Updated window.py:

import tkinter as tk import frame_display import frame_botoes

class Main(tk.Tk):
    def __init__(self):
        super().__init__()
        self.geometry("640x640")
        self.visor = frame_display.DisplayContainer(self)
        self.numeros = frame_botoes.ButtonsContainer(self)

Main().mainloop()

Updated calculadora.py:

agregator = ""
result = ""


def pressNumber(num, window):
    global agregator
    global result
    agregator = agregator + str(num)
    result = agregator
    window.visor.updateTextDisplay(result)


def pressEqual(window):
    try:
        global agregator
        total = str(eval(agregator))
        window.visor.updateTextDisplay(total)
        agregator = ""
    except ZeroDivisionError:
        window.visor.updateTextDisplay("Erro: Divisão por zero")
        agregator = ""
    except:
        window.visor.updateTextDisplay("Error")
        agregator = ""

def pressClear(window):
    global agregator
    agregator = ""
    window.visor.updateTextDisplay("Clear")

Updated frame_botoes.py:

import tkinter as tk
from tkinter import Frame
import calculadora


class ButtonsContainer(Frame):

    def __init__(self , root):
        Frame.__init__(self, root)
        self.parent = root
        self.configure(bg="yellow")
        self.parent.bind("<Key>", self.keyHandler)
        self.parent.bind("<Return>", self.returnKeyHandler)


        # Layout ButtonsContainer
        self.grid(row=1 , column=0 , sticky ="nsew")
        self.parent.rowconfigure(1, weight=1)
        self.parent.columnconfigure(0, weight=1)

        # Call ButtonsContainer widgets creation
        self.createWidgets()


    # Create widgets for ButtonsContainer
    def createWidgets(self):

        button_padx = 15
        button_pady = 15

        self.button_1 = tk.Button(self, text="1", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(1, self.parent))
        self.button_2 = tk.Button(self, text="2", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(2, self.parent))
        self.button_3 = tk.Button(self, text="3", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(3, self.parent))
        self.button_4 = tk.Button(self, text="4", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(4, self.parent))
        self.button_5 = tk.Button(self, text="5", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(5, self.parent))
        self.button_6 = tk.Button(self, text="6", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(6, self.parent))
        self.button_7 = tk.Button(self, text="7", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(7, self.parent))
        self.button_8 = tk.Button(self, text="8", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(8, self.parent))
        self.button_9 = tk.Button(self, text="9", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(9, self.parent))
        self.button_0 = tk.Button(self, text="0", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(0, self.parent))

        self.button_open_parens = tk.Button(self, text="(", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber("(", self.parent))
        self.button_close_parens = tk.Button(self, text=")", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(")", self.parent))


        self.button_dot = tk.Button(self, text=".", padx= button_padx, pady=button_pady, command=lambda: calculadora.pressNumber(".", self.parent))
        self.button_plus = tk.Button(self, text="+", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber("+", self.parent))
        self.button_minus = tk.Button(self, text="-", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber("-", self.parent))
        self.button_multiply = tk.Button(self, text="*", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber("*", self.parent))
        self.button_divide = tk.Button(self, text="/", padx=button_padx, pady=button_pady, command=lambda: calculadora.pressNumber("/", self.parent))
        self.button_equal = tk.Button(self, text="=", padx=button_padx, pady=button_pady, command=calculadora.pressEqual(self.parent))
        self.button_clear = tk.Button(self, text="CLEAR", padx=button_padx, pady=button_pady, command=calculadora.pressClear(self.parent))

    # Layout widgets for ButtonsContainer
        self.button_1.grid(row=0, column=0, sticky="nswe")
        self.button_2.grid(row=0, column=1, sticky="nswe")
        self.button_3.grid(row=0, column = 2, sticky="nswe")
        self.button_4.grid(row=1, column=0, sticky="nswe")
        self.button_5.grid(row=1, column=1, sticky="nswe")
        self.button_6.grid(row=1, column=2, sticky="nswe")
        self.button_7.grid(row=2, column=0, sticky="nswe")
        self.button_8.grid(row=2, column=1, sticky="nswe")
        self.button_9.grid(row=2, column=2, sticky="nswe")

        self.button_open_parens.grid(row=3, column=0, sticky="nswe")
        self.button_close_parens.grid(row=3, column=2, sticky="nswe")

        self.button_0.grid(row=3, column=1, sticky="nswe")
        self.button_dot.grid(row=4, column=2, sticky="nswe")
        self.button_plus.grid(row=0 , column=3, sticky="nswe")
        self.button_minus.grid(row=1 , column=3, sticky="nswe")
        self.button_multiply.grid(row=2 , column=3, sticky="nswe")
        self.button_divide.grid(row=3 , column=3, sticky="nswe")

        self.button_equal.grid(row=4 , column=3, sticky="nswe")
        self.button_clear.grid(row=4 , columnspan=2, sticky="nswe")

        for x in range(0,5):
            self.rowconfigure(x, weight=1)

        for i in range(0, 4):
            self.columnconfigure(i, weight=1)

    #Bind keyboard events
    def keyHandler(self, event):
        calculadora.pressNumber(event.char, self.parent)

    #Bind Return key
    def returnKeyHandler(self, event):
        calculadora.pressEqual()

Now that the quick fix is dealt with its time to go in depth as to the other formatting issues and PEP8 changes we should make.

I will keep each one of your files separate but honestly I do not think it is necessary to separate the main window file from the frame date.

1st: I would like to address is PEP8 standards. Personally I think you should use CamelCase for Class names and lowercase_with_underscores for functions/methods.

2nd: Lets look at your buttons in frame_botoes. You should probably be generating your buttons with loops so we can keep the code short and clean. I have 2 examples here. One uses simple counting for the layout and the other uses a list with grid values for placement.

3rd: We should avoid using global so lets convert your calculadora functions into a class that we use with class attribute to manage the aggregator.

4th: You only need self. prefix for a variable that will be changed later in the class outside of the method it is generated in. So for all your buttons we can remove this prefix. At the same time we don't need to name them as we are generating them from a loop. Naming doesn't help us here as the layout is simple enough and we are not changing the buttons later.

5th: We do not need from tkinter import Frame as you are already using import tkinter as tk so we can simply call tk.Frame or any other widget for that matter where it is needed.

With some general clean up and the things I mentioned above here is your modified code:

New window.py:

import tkinter as tk
import frame_display
import frame_botoes


class Main(tk.Tk):
    def __init__(self):
        super().__init__()
        self.geometry("640x640")
        self.columnconfigure(0, weight=1)
        self.rowconfigure(1, weight=1)
        self.visor = frame_display.DisplayContainer().grid(row=0, column=0, sticky="new")
        self.numeros = frame_botoes.ButtonsContainer().grid(row=1, column=0, sticky="nsew")

Main().mainloop()

New calculadora.py:

class Press:
    def __init__(self, master):
        self.master = master
        self.aggregator = ''

    def num(self, n):
        self.aggregator += str(n)
        self.master.visor.update_text_display(self.aggregator)

    def equal(self, _):
        try:
            total = str(eval(self.aggregator))
            self.aggregator = ''
            self.master.visor.text_display.set(total)
        except ZeroDivisionError:
            self.master.visor.text_display.set("Error: Divisão por zero")
        except:
            self.master.visor.text_display.set("Unexpected error")
            raise

    def clear(self):
        self.master.visor.text_display.set("Clear")

New frame_display.py:

import tkinter as tk


class DisplayContainer(tk.Frame):
    def __init__(self):
        super().__init__()
        self.configure(bg="cyan", height=5)
        self.columnconfigure(0, weight=1)
        self.txt = tk.StringVar()

        label_display = tk.Label(self, textvariable=self.txt, font=15, bg="#bebebe", relief="groove", bd=5, height=5)
        label_display.grid(row=0, column=0, sticky="nsew")

    def update_text_display(self, text):
        self.text_display.set(text)

New frame_botoes.py:

import tkinter as tk
import calculadora


class ButtonsContainer(tk.Frame):
    def __init__(self):
        super().__init__()
        self.configure(bg="yellow")
        self.screen = calculadora.Press(self.master)
        self.master.bind("<Key>", self.key_handler)
        self.master.bind("<Return>", self.screen.equal)
        for x in range(0, 5):
            self.rowconfigure(x, weight=1)
            if x < 4:
                self.columnconfigure(x, weight=1)

        pad = 15
        r = 0
        c = 0
        for i in range(10):
            if i == 0:
                tk.Button(self, text=i, padx=pad, pady=pad,
                          command=lambda n=i: self.screen.num(n)).grid(row=3, column=1, sticky="nswe")
            else:
                tk.Button(self, text=i, padx=pad, pady=pad,
                          command=lambda n=i: self.screen.num(n)).grid(row=r, column=c, sticky="nswe")
                if c == 2:
                    c = 0
                    r += 1
                else:
                    c += 1

        for i in [["-", 1, 3], ["*", 2, 3], ["/", 3, 3], ["(", 3, 0],
                  [")", 3, 2], [".", 4, 2], ["+", 0, 3], ["=", 4, 3], ["CLEAR", 4, 0]]:
            if i[0] == 'CLEAR':
                tk.Button(self, text=i[0], padx=pad, pady=pad,
                          command=self.screen.clear).grid(row=i[1], column=i[2], columnspan=2, sticky="nsew")
            elif i[0] == '=':
                tk.Button(self, text=i[0], padx=pad, pady=pad,
                          command=self.screen.equal).grid(row=i[1], column=i[2], sticky="nsew")
            else:
                tk.Button(self, text=i[0], padx=pad, pady=pad,
                          command=lambda v=i[0]: self.screen.num(v)).grid(row=i[1], column=i[2], sticky="nsew")

    def key_handler(self, event):
        self.screen.num(event.char)

If you have any questions let me know :D