How to create new log file for each run of tests in pytest?

Question

I have created a pytest.ini file,

addopts = --resultlog=log.txt

This creates a log file, but I would like to create a new log file everytime I run the tests.

Answer 1

Answering my own question. As hoefling mentioned --result-log is deprecated, I had to find a way to do it without using that flag. Here's how I did it,

conftest.py

from datetime import datetime
import logging

log = logging.getLogger(__name__)

def pytest_assertrepr_compare(op, left, right):
    """ This function will print log everytime the assert fails"""
    log.error('Comparing Foo instances:    vals: %s != %s \n' % (left, right))
    return ["Comparing Foo instances:", " vals: %s != %s" % (left, right)]

def pytest_configure(config):
    """ Create a log file if log_file is not mentioned in *.ini file"""
    if not config.option.log_file:
        timestamp = datetime.strftime(datetime.now(), '%Y-%m-%d_%H-%M-%S')
        config.option.log_file = 'log.' + timestamp

pytest.ini

[pytest]
log_cli = true
log_cli_level = CRITICAL
log_cli_format = %(message)s
log_file_level = DEBUG
log_file_format = %(asctime)s [%(levelname)8s] %(message)s (%(filename)s:%(lineno)s)
log_file_date_format=%Y-%m-%d %H:%M:%S

test_my_code.py

import logging
log = logging.getLogger(__name__)

def test_my_code():
    ****test code