Why can a program find Pandas when running in Spyder, but not in R studio?

I'm on Windows 10 running Python 3.8.2. I've got a program that reads an excel file and makes a new one based on the information inside. The program works perfectly in Spyder, but when run in R studio is gives me a ModuleNotFoundError: No module named 'pandas'. It continues until it needs pandas at the read_file line, then throws an exception because pandas is not defined. Spyder is version 4.1.3, R studio is version 1.2.1335

This is a truncated version of my full code (it doesn't make the new excel file) but it has the same problem.

Code used:

import pandas
import os
import tkinter as tk
from tkinter import messagebox
from tkinter import filedialog

class app():      
    def __init__(self,root):
        self.root=root
        self.file=None
        while self.file == None:
            try:
                self.file = filedialog.askopenfile(parent=root,mode='rb',title='Choose a file')                   # Select the file with the list
                read_file = pandas.read_excel(self.file, sheet_name='Sheet 1            ')               # reads the file in
                read_file.to_csv (os.getcwd()+"\\CSV.csv", index = None, header=True)                       # convert to csv to make into a datafram
                self.df = pandas.read_csv(os.getcwd()+"\\CSV.csv",)     # make into dataframe
   
            except IOError:
                messagebox.showinfo(message="The file you are trying to edit is still open.  Please close it and try again")
                self.Repeat()
            except Exception as e:
                print(e)
                self.Repeat()
        
    def Repeat(self):                                                                                
        self.file="a"                                                                                     # dialog box for if there's an error.  Asks if you want to try again or cancel the program 
        if messagebox.askretrycancel("askretrycancel", "Try again?"):  
           self.file=None
        else:
            root.destroy()
        
        
root=tk.Tk()
app=app(root)
root.mainloop()

Edit:

So, I followed the link that @Trenton McKinney gave, and made sure that everything was set up correctly. As far as I can tell it is working correctly. I also tried two simple scripts. The first just tries to import pandas and print hello world.

import pandas


print('Hello World!')

This gives the same ModuleNotFoundError: No module named 'pandas' error as before, and then prints 'Hello World!'. The second code does the same think but imports tkinter to print a message box

import pandas
import tkinter
from tkinter import messagebox

root=tkinter.Tk()
print('Hello World!')
messagebox.showinfo(message="Hello World!")
root.destroy()

This one also gives an error for importing pandas, but the rest runs correctly, so R Studio is able to import libraries at least. Any help is appreciated.

Make sure your RStudio is using the same Python as your Spyder. This can easily be done if you're using Anaconda (just ensure you're doing everything in the same environment).