In Python 3.5 and newer use the new recursive **/ functionality:
configfiles = glob.glob('C:/Users/sam/Desktop/file1/**/*.txt', recursive=True)
When recursive is set, ** followed by a path separator matches 0 or more subdirectories.
In earlier Python versions, glob.glob() cannot list files in subdirectories recursively.
In that case I'd use os.walk() combined with fnmatch.filter() instead:
import os
import fnmatch
path = 'C:/Users/sam/Desktop/file1'
configfiles = [os.path.join(dirpath, f)
for dirpath, dirnames, files in os.walk(path)
for f in fnmatch.filter(files, '*.txt')]
This'll walk your directories recursively and return all absolute pathnames to matching .txt files. In this specific case the fnmatch.filter() may be overkill, you could also use a .endswith() test:
import os
path = 'C:/Users/sam/Desktop/file1'
configfiles = [os.path.join(dirpath, f)
for dirpath, dirnames, files in os.walk(path)
for f in files if f.endswith('.txt')]