You can simply do:

my_text = my_button['text']

Tkinter allows you to access any option of a widget this way (height, width, text, etc.)

If you need this as a method call, you can use .cget:

my_text = my_button.cget('text')

Note that this method is available on all standard Tkinter widgets.

Ok so here is an example using a class to perform what I think it is you are asking.

You want to use lambda in your command and assign the value of text to a variable. Then you pass that variable to the getTest(self, text) method to be able to print your button.

From your comment

Whole code is not need i just need way to get buttons text nothing else

I have created a bit of code to illustrate what you are wanting.

EDIT: I have added code that will allow you to change the configs of the button as well.

import tkinter as tk

# created this variable in order to test your code.
seznamTextu = ["1st Button", "2nd Button", "3rd Button", "4th Button", "5th Button"]

class MyButton(tk.Frame):
    def __init__(self, parent, *args, **kwargs):
        tk.Frame.__init__(self, parent, *args, **kwargs)
        self.parent = parent
        self.obsahOkna()
    def obsahOkna(self):

        radek = 0
        bunka = 0
        for i in range(5):
            btn = tk.Button(self.parent, text=seznamTextu[i])
            btn.config(command= lambda t=seznamTextu[i], btn = btn: self.getText(t, btn))
            # in order for this to work you need to add the command in the config after the button is created.
            # in the lambda you need to create the variables to be passed then pass them to the function you want.
            btn.grid(row=radek, column=bunka)

            bunka += 1
            if bunka == 2 : # changed this variable to make it easier to test code.
                bunka = 0
                radek +=1

    def getText(self, text, btn):
        btn.configure(background = 'black', foreground = "white")
        print("successfully called getText")
        print(text)


if __name__ == "__main__":
    root = tk.Tk()
    myApp = MyButton(root)


    root.mainloop()

Here is the result of running the program and pressing a couple buttons.

At first glance, there are a couple of things wrong here. First of all, your for loop needs to be indented four spaces like this:

for c in range(0, 5):
    b.append(Button(a, text=c, command=lambda: command(c))
    b[c].pack()

If you don't do that, then the value of c will be 4 for the rest of the script because that is the value of c for the last iteration of range(0, 5).

The reason that your buttons are always printing 4 is because the variable c is evaluated when the callback is called, not when you assign the callback to the button. A simple way to avoid this problem is to initialize the lambda function with the current value of c using a dummy variable (we'll call it j) like this: lambda j=c: command(j). Putting this together, you should have something like this :

from tkinter import *    

def command(d):
   print(d)

a = Tk()
b = []

for c in range(0, 5):
    x = Button(a, text=c, command=lambda j=c: command(j))
    x.pack()
    b.append(x)

a.mainloop()

I changed the way you packed the button because I think it's far more readable, but the end result should be the same.

You can do it by making the command a lambda function with an argument that has a default value that's what you want passed to it. Below is an example of what I mean. The slightly tricky part is creating the lambda with an argument that is the widget it is with. In the code below, this is done by separating the Button creation from the configuring its command option, which is now done after they all exist.

from tkinter import *

root = Tk()

def clicked(btn):
    btn_text = btn.cget('text')
    message = Label(root, text=f'You clicked button "{btn_text}".')
    message.pack()

buttons = [
    Button(root, text="Nice day for coding ain't it?", state=ACTIVE, padx=200, pady=5),
    Button(root, text="What does evil Morty want?", state=ACTIVE, padx=200, pady=5),
    Button(root, text="Microsoft Edge==Chrome downloader", state=ACTIVE, padx=200, pady=5),
    Button(root, text="Only real programmers use Mac", state=ACTIVE, padx=200, pady=5),
]

for button in buttons:
    button.config(command=lambda btn=button: clicked(btn))
    button.pack(fill=X)

root.mainloop()

To sum up this thread: button.config and button.configure both work fine!

button.config(text="hello")

or

button.configure(text="hello")

Calling the element in a list which contains a tkinter Button widget will return the widget itself as if you were calling any other value stored in an element of a list. Meaning that if you wanted the text attribute of the value of the element you could use ["text"] or .cget("text").

See below:

from tkinter import *

root = Tk()

array = [Button(root, text="1"), Button(root, text="2"), Button(root, text="3")]

for i in array:
    print(type(i))
    print(i.cget("text"))
    print(i["text"])