如何将变量分配给 eval / exec 值？

Question

is it possible to assign a variable to a exec / eval value? this is what i tried

def execute ():
    run_wn = tk.Tk() 
    des1 = tk.Label(run_wn, text = "------------------------------").pack()
    run_value = exec(cmd.get("1.0", "end"))
    value = tk.Label(run_wn, text = run_value)
    des2 = tk.Label(run_wn, text = "------------------------------").pack()
    run_wn.mainloop
bt = tk.Button(wn, text = "run", command = execute).pack()

the cmd is a text box.. when i execute this code then it does not return anything in the run screen. it prints it is there any way you can asign a value to a exec / eval value and and use it as text in a Label??

this is just a experimental project..

help will be very appreciated!!

thanks

Answer 1

exec takes two other positional arguments, dictionaries for globals and locals, so you could exec like this to capture results in a dict:

In [1]: ns = {}
In [2]: exec("p = 1 + 2", globals(), ns)

In [3]: ns
Out[3]: {'p': 3}

Exec'ing untrusted code is dangerous. Don't do it if you're mixing user input into the commands unless you really know what you're doing.