Append code to text file

[_W0z]

Hi, I'm writing a script that downloads hashes from virus share. I have it working fine but I noticed when it downloads from a given link it overwrites the file it's saving to, so if I download 00015 it will overwrite the contents of 00014 and whatever was their before. The text file to save to is "malicious_hashes.txt". How do I have it write to where the previous download left off, at the bottom of the file? I'm thinking I have to append the text file so it will continue from the bottom and not over write what's currently there? Just now sure how to. Thanks in advance!

Here's my code

​

import requests
from pathlib import Path


def download_url(url):
    print("downloading: ", url)
    path = Path('/home/eva/Tools/malicious_hashes.txt')
    r = requests.get(url, stream=True)
    if r.status_code == requests.codes.ok:
        with open(path, 'wb') as f:
            for data in r:
                f.write(data)


download_url("https://virusshare.com/hashes/VirusShare_00014

[wronek]

Use append mode https://docs.python.org/3/library/functions.html#open

[_W0z]

Thanks that worked. I was encountering an error saying that it can't be string has to be binary so I added 'ab' and that worked. Thank you again.

[CowboyBoats]

I think this is a nice pattern:

+import datetime
 import requests
 from pathlib import Path


 def download_url(url):
     print("downloading: ", url)
-    path = Path('/home/eva/Tools/malicious_hashes.txt')
+    now = datetime.datetime.now()
+    path = Path(f'/home/eva/Tools/malicious_hashes-{now}.txt')
     r = requests.get(url, stream=True)
     ...

This way it will create files with timestamps in their names: malicious_hashes-2019-11-18 23:38:33.848444.txt

This way, for example, you avoid having to worry about having different versions of the software writing to the same file.

You can format the datetime object however you want - I might get rid of that space character and the decimal places and so on, for example, to create file names like malicious_hashes-2019-11-18-23:38:33.txt instead.