I am getting a 'str' object has no attribute 'get' error (Python) with Tkinter Entry Box

Question

I am currently working on a project where I will have a plethora of equations and laws from different subject areas within a calculator with GUI functionality. This project is a learning process and all help is appreciated. I am currently having trouble with the Tkinter Entry boxes, more specifically retrieving the values behind string variables. Every time I attempt to use .get() my Entry boxes return an error, 'str' object has no attribute 'get' , which I can't figure out. I would also really appreciate if someone could help trim the fat of my code and minimize the bulk.

The issue is occurring in class ReactionProp() in Science_Calculator.py . Thanks to all who respond!

PS Sorry about weird formatting lol

from tkinter import *
import tkinter as tk
import math

"""    Calculator     """     
class CalculatorGUI(tk.Tk):
   def __init__(self, *args, **kwargs):
       
       tk.Tk.__init__(self, *args, **kwargs)
       container = tk.Frame(self)

       container.pack(expand = True)

       container.grid_rowconfigure(0)
       container.grid_columnconfigure(0)

       self.frames = {}

       for F in ([ReactionProp]):

           frame = F(container, self)

           self.frames[F] = frame

           frame.grid(row=0, column=0, sticky=NS)

       self.show_frame(ReactionProp)

   def show_frame(self, cont):

       frame = self.frames[cont]
       frame.tkraise()

class ReactionProp(tk.Frame):       
   def __init__(self, parent, controller):
       tk.Frame.__init__(self,parent)
       
       checkT = tk.DoubleVar(self)
       r1 = tk.StringVar(self)
       r2 = tk.StringVar(self)
       r3 = tk.StringVar(self)
       r4 = tk.StringVar(self)
       r5 = tk.StringVar(self)
       p1 = tk.StringVar(self)
       p2 = tk.StringVar(self)
       p3 = tk.StringVar(self)
       p4 = tk.StringVar(self)
       p5 = tk.StringVar(self) 
       
       """    Activation Code     """
       def SolveReactionProp():
           Calculate = Calculator()  #Refers to Calculator Class
           
           r1 = ''
           r2 = ''
           r3 = ''
           r4 = ''
           r5 = ''
           p1 = ''
           p2 = ''
           p3 = ''
           p4 = ''
           p5 = ''
           
           if r1.get():
               r1 = var1.get()
           if z2.get():
               r2 = var2.get()
           if r3.get():
               r3 = var3.get()
           if r4.get():
               r4 = var4.get()
           if r5.get():
               r5 = var5.get()
           if p1.get():
               r6 = var6.get()
           if p2.get():
               r7 = var7.get()
           if p3.get():
               r8 = var8.get()
           if p4.get():
               r9 = var9.get()
           if p5.get():
               r10 = var10.get()
                       
           Calculate.ReactionProp()
       
       Label(self, text='Thermodynamics - Reaction Properties', font='Helvetica 24 bold').grid(row=0,column=0,columnspan=4,padx=(100),pady=(0,30))
       
       Radiobutton(self,text='Temperature (K)',font='Helvetica 14',variable=checkT,value=1).grid(row=1,column=0,columnspan=2,sticky=EW,pady=(0,25))
       Radiobutton(self,text='No Temperature',font='Helvetica 14',variable=checkT,value=0).grid(row=2,column=0,columnspan=2,sticky=EW,pady=(0,25))
       tE = Entry(self,width=40)
       tE.grid(row=1,column=2,columnspan=2,pady=(35,0),sticky=W)
   
       Label(self, text='Reactants:',font='Helvetica 14').grid(row=3,column=0,columnspan=2)
       r1 = Entry(self,width=40)
       r1.grid(row=4,column=0,columnspan=2,pady=(25,0))
       r2 = Entry(self,width=40)
       r2.grid(row=5,column=0,columnspan=2,pady=(25,0))
       r3 = Entry(self,width=40)
       r3.grid(row=6,column=0,columnspan=2,pady=(25,0))
       r4 = Entry(self,width=40)
       r4.grid(row=7,column=0,columnspan=2,pady=(25,0))
       r5 = Entry(self,width=40)
       r5.grid(row=8,column=0,columnspan=2,pady=(25,0))
       
       Label(self, text='Products:',font='Helvetica 14').grid(row=3,column=2,columnspan=2)
       p1 = Entry(self,width=40)
       p1.grid(row=4,column=2,columnspan=2,pady=(25,0))
       p2 = Entry(self,width=40)
       p2.grid(row=5,column=2,columnspan=2,pady=(25,0))
       p3 = Entry(self,width=40)
       p3.grid(row=6,column=2,columnspan=2,pady=(25,0))
       p4 = Entry(self,width=40)
       p4.grid(row=7,column=2,columnspan=2,pady=(25,0))
       p5 = Entry(self,width=40)
       p5.grid(row=8,column=2,columnspan=2,pady=(25,0))
       
       Button(self, text="Solve", font ='Helvetica 12 bold', command=SolveReactionProp).grid(row=9,column=1,pady=(100,0))
       Button(self, text="Return", font='Helvetica 12 bold', command=lambda:[controller.show_frame(ThermoTab)]).grid(row=9,column=2,pady=(100,0))

start  = CalculatorGUI()
start.mainloop()      

Error Code:

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\Heath\anaconda3\lib\tkinter\__init__.py", line 1883, in __call__
    return self.func(*args)
  File "C:\Users\Heath\Documents\Science Calculator Project\untitled0.py", line 69, in SolveReactionProp
    if r1.get():

Answer 1

The problem is in SolveReactionProp function.You must remove this.

       r1 = ''
       r2 = ''
       r3 = ''
       r4 = ''
       r5 = ''
       p1 = ''
       p2 = ''
       p3 = ''
       p4 = ''
       p5 = ''

Explanation: In SolveReactionProp You typecasted or defined r1,r2 and other variables as python strings. So when you use .get() function you got the error because.get() is attribute of tk.StringVar() not of python strings.