Checking if a list of files exists before proceeding?

Question

I have some pandas code running for 9 different files each day. Currently, I have a scheduled task to run the code at a certain time but sometimes the files have not been uploaded to the SFTP by our client on time which means that the code will fail. I want to create a file checking script.

Answer 1

import os, time

filelist = ['file1','file2','file3']

while True:
    list1 = []

    for file in filelist:
        list1.append(os.path.isfile(file))

    if all(list1):
        # All elements are True. Therefore all the files exist. Run %run commands
        break
    else:
        # At least one element is False. Therefore not all the files exist. Run FTP commands again
        time.sleep(600) # wait 10 minutes before checking again

all() checks if all the elements in the list are True. If at least one element is False it returns False.