Python 3: make a function go through all possible arguments without generating any errors

Question

I want to open a file called text_file1.txt and see the content. That file can be located anywhere on the host machine, though it's in some subdirectory beneath /Users/BobbySpanks. In the code below roots will store all the absolute pathnames of subdirectories starting from /Users/BobbySpanks, but without a / at the end. I add a / and then text_file1.txt to all subdirectory pathanmes in roots in a variable called abs_path so that the file I want to read has a proper absolute pathname syntax. So the problem is, I get a FileNotFound error when I try to open the file. I want the fo variable, which opens the file (using the absolute pathname), to go through all of the possible absolute pathnames that text_file1.txt can have. So I don't want the script to stop at the first possible absolute pathname, I want it to go through all of them until it finds the right pathname of text_file1.txt.

import os

filename = "text_file1.txt"

top_directory = r"/Users/BobbySpanks/"

for roots, dirs, files in os.walk(top_directory):
    ff = roots + "/"
    abs_path = ff + filename

file_open = open(abs_path, "r")
file_read = file_open.read()
print(file_read)