loop through folder in python and open files throws an error

Question

I try to loop through folder and read files but only the first file will open and read correctly but the second files print the name and through an error "IOError: [Errno 2] No such file or directory:". I have tried the following

for filename in os.listdir("pathtodir\DataFiles"):
    if filename.endswith(".log"): 
        print(os.path.join("./DataFiles", filename))

        with open(filename) as openfile:    
        for line in openfile:
        ........

Answer 1

os.listdir() gives you only the filename, but not the path to the file:

import os

for filename in os.listdir('path/to/dir'):
    if filename.endswith('.log'):
        with open(os.path.join('path/to/dir', filename)) as f:
            content = f.read()

Alternatively, you could use the glob module. The glob.glob() function allows you to filter files using a pattern:

import os
import glob

for filepath in glob.glob(os.path.join('path/to/dir', '*.log')):
    with open(filepath) as f:
        content = f.read()