python - Reading the contents of a file whose name is stored in a variable

Question

The following code first creates a list of all the files in a folder called films, then attempts to access the contents of a specific file. I know how to do this if the file's name is a literal, but can someone please explain how this can be done if the name of the file or the directory is a variable?

path = 'films'

from os import walk

f = []
for (filenames) in walk(path):
    f.extend(filenames) 
    break

listoffiles = f[2]
print("listoffiles: ",listoffiles)  
 
read = open('films/{listoffiles[0]}',"r")
print("read: ",str(read.read()))

Answer 1

just change it to be

read = open(f'films/{listoffiles[0]}',"r")