Different ways to read all files from a directory using python

gist_create_file_lists.py

# Knowing a base `dirpath` retrieve all files starting with `NV` and with file extension `.img`
from glob import glob
onlyfiles = glob( '{}/NV*.img'.format(dirpath))
#
import glob
onlyfiles = glob.glob("/home/adam/*.txt"))

# List recursibly in `dirpath` all the `.tif` files if `mygroup` is in filename and does not include `DEPRECIATED`
onlyfiles = [y for x in os.walk(dirpath) for y in glob(os.path.join(x[0], '*.tif')) if mygroup[:-2] in y and 'DEPRECIATED' not in y]

#
from os import listdir
from os.path import isfile, join
onlyfiles = [f for f in listdir(dirpath) if isfile(join(dirpath, f))]

#
from os import walk

f = []
for (dirpath, dirnames, filenames) in walk(mypath):
    # extending the list `f`
    f.extend(filenames)
    break
    
### find all the filenames in the dirpath which are files and have an extension name of `.txt`
[name for name in os.listdir(dirpath) if os.path.isfile(os.path.join(dirpath, name)) and '.txt' in name]

Added another example