Running specific views.py method on django_cron

Question

I have this method on my views.py file:

def getHistoricRates():
    """ Here we have the function that will retrieve the historical rates from fixer.io, since last month """
    rates = {}
    response = urlopen('http://data.fixer.io/api/2018-12-31?access_key=c2f5070ad78b0748111281f6475c0bdd')
    data = response.read()
    rdata = json.loads(data.decode(), parse_float=float) 
    rates_from_rdata = rdata.get('rates', {})
    for rate_symbol in ['USD', 'GBP', 'HKD', 'AUD', 'JPY', 'SEK', 'NOK', 'EUR']:
        try:
            rates[rate_symbol] = rates_from_rdata[rate_symbol]
        except KeyError:
            logging.warning('rate for {} not found in rdata'.format(rate_symbol)) 
            pass

    return rates

@require_http_methods(['GET', 'POST'])
def historical(request):
    date_str = "2018-12-31"
    if datetime.datetime.strptime(date_str,"%Y-%m-%d").weekday()<5:
        rates = getHistoricRates()
        fixerio_rates = [Fixerio_rates(currency=currency, rate=rate)
                     for currency, rate in rates.items()]
        Fixerio_rates.objects.bulk_create(fixerio_rates) 
        return render(request, 'historical.html')

I want to run historical at 9am every day, except for weekends.

Now, I can't find any example on how to run an existent method, or how to call it from the cron.py file whatsoever.

I do have everything configured, for django_cron but I just can't figure out how to "use" this method from my cron file to run it at specific times.

This is my cron.py file so far:

from django_cron import CronJobBase, Schedule
from .views import historical

class MyCronJob(CronJobBase):
    RUN_AT_TIMES = ['9:00']

    schedule = Schedule(run_at_times=RUN_AT_TIMES)
    code = 'fixerio.my_cron_job'    # a unique code

    def do(self):
        pass    # do your thing here

The name fixerio is my app's name.

Any ideas on this?

What? Your cron code has a comment "do your thing here". Why can't you do the thing there? — Daniel Roseman, Jan 13 '19 at 20:21
You mean, can I just "wrap" this django_cron around the function I have? Sorry about the stupid question. — NeoVe, Jan 13 '19 at 20:25
`historical()` is a view. Presumably it's the `bulk_create()` part that you're interested in doing at 9am every day, rather than making a HTTP request from the cronjob. — Will Keeling, Jan 13 '19 at 21:51
Yeah, that's correct, can I just use that statement into my cron.py file? Just by importing the views.py content into it? — NeoVe, Jan 13 '19 at 21:57

Will Keeling · Accepted Answer · 2019-01-14T08:48:58.117

1

Since you're looking to call the getHistoricRates() and the bulk_create() logic from both your historical() view and also a cron job, it would be better to first refactor that common code from the view into a separate module - for example into helpers.py that lives alongside the views.py and cron.py.

helpers.py

from .models import Fixerio_rates

def create_rates():
    rates = getHistoricRates()
    fixerio_rates = [Fixerio_rates(currency=currency, rate=rate)
                     for currency, rate in rates.items()]
    Fixerio_rates.objects.bulk_create(fixerio_rates) 

def getHistoricRates():
    ...

You can then invoke that from your cron job:

cron.py

from .helpers import create_rates

class MyCronJob(CronJobBase):
    RUN_AT_TIMES = ['9:00']

    schedule = Schedule(run_at_times=RUN_AT_TIMES)
    code = 'fixerio.my_cron_job'    # a unique code

    def do(self):
        create_rates()

And also from your view:

views.py

from .helpers import create_rates

@require_http_methods(['GET', 'POST'])
def historical(request):
    date_str = "2018-12-31"
    if datetime.datetime.strptime(date_str,"%Y-%m-%d").weekday()<5:
        create_rates()
        return render(request, 'historical.html')

edited Jan 14 '19 at 08:48

answered Jan 13 '19 at 22:39

Will Keeling

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Hi Sir, looks fantastic, thank you very much, just one question, can I import something into the helpers.py file, like views * or models *? See, I'm importing that, but it says it has no attribute 'items', ´for currency, rate in rates.items()]´ – NeoVe Jan 13 '19 at 23:17
1

Yes you can import models into `helpers.py` - I have updated the answer to illustrate importing `Fixerio_rates`. You shouldn't import anything from `views.py` - because the dependency relationship is from `views.py` -> `helpers.py` not the other way round. With regard to the attribute error for `items`, that is odd because `items()` is a method on `dict` which is being returned from `getHistoricRates()` – Will Keeling Jan 14 '19 at 08:48
Hi Will, thanks, yes, but that's the point, it's like getHistoricRates isn't being returned for some reason, I ask, should I have getHistoricRates() as it is on the very same helpers.py file? – NeoVe Jan 14 '19 at 10:55
1

Yes `getHistoricRates()` can live in `helpers.py` together with the new `create_rates()` function. Are you definitely calling `getHistoricRates()` (have you accidentally omitted the brakets)? Perhaps you could post the last few lines from the traceback? – Will Keeling Jan 14 '19 at 12:02
Hi Will, thanks a lot, I just added the code as explained in my last comment, so, now is working wonderfully, thanks again! Cheers! – NeoVe Jan 14 '19 at 17:29

Running specific views.py method on django_cron

1 Answers1