How to timestamp output text files

Question

This seems relevant but I cannot decipher this and apply it to my problem.

Python output file with timestamp

After going through API authorization, I want this website to dump my data every time I call coinbase.py. Here are my relevant lines:

transdata =  get_http('https://coinbase.com/api/v1/transfers').read()

f1 = open('./DUMP.txt', 'w+')

f1.write( transdata )

This will overwrite DUMP.txt every time its called. How can I ask python to assign the output file a new name each time this module is calld, conserving the old outputs...and make the name as logical as I can (perhaps with a time and date of the call)?

Answer 1

You can prepend a linux timestamp by using time.time() and converting the float to an integer:

import time

transdata =  get_http('https://coinbase.com/api/v1/transfers').read()
f1 = open('{}_DUMP.txt'.format(int(time.time())), 'w+')
f1.write( transdata )

I'd use the with-statment so your file is actually handled correctly:

import time

with open("{}_DUMP.txt".format(int(time.time()), 'w+') as out:
    out.write(get_http('https://coinbase.com/api/v1/transfers').read())

The time and datetime modules provide all you need for handling time on python.

Or if you want a date and time, a quick way to do that is to use datetime.datetime.now():

from datetime import datetime

with open("{}_DUMP.txt".format(datetime.datetime.now(), 'w+') as out:
    out.write(get_http('https://coinbase.com/api/v1/transfers').read())

Answer 2

Consider using tempfile https://docs.python.org/2/library/tempfile.html which allows creation of unique file, even with defined name prefix.

But what you describe is usually resolved by dumping the data into one log file, you do not get you directory cluttered with too many files.