Listing files in a folder can be done with the os or glob library in Python.

List all files in a folder

# List all files
import os
folder = 'my_data'
files_list = [f for f in os.listdir(folder)]

List files that match a condition

# List files which name ends with `.txt`
import os
folder = 'my_data'
files_list = [f for f in os.listdir(folder) if f.endswith('.txt')]

Alternatively, you can use the glob library:

# List files which name contains `_log_`
import glob
folder = 'my_data/'
files_list = glob.glob(folder + '*_log_*')

Recursively find files in subfolders

To find all files in subfolders, the easiest way since Python 3.5 is to use glob.glob() with the recursive parameter.

# List CSV files which name contains `_log_`, also searching in subfolders
import glob
folder = 'my_data/'
files_list = glob.glob(folder + '/**/*_log_*.csv', recursive=True)

List files in a folder with Python

List all files in a folder

List files that match a condition

Recursively find files in subfolders