Put the call to get_regular_expression
at the module level:
str_re = get_regular_expression()
@celery.task
def analyse_json(tw):
re.match(str_re, tw.text)
It will only be called once, when the module is first imported.
Additionally, if you must have only one instance of your worker running at a time (for example CUDA), you have to use the -P solo option:
celery worker --pool solo
Works with celery 4.4.2.