added new generic rss fetch and parse functions and setup to store not only today value but all values in file and update if new are available.

django/didgeridoo/currencies/exchange_rates.py

@@ -11,61 +11,30 @@ Key:Value pairs of new currencys.
 """
 
 
-def get_exchange_rate():
+def get_rss(url):
-    # zweitweise kann die resource nicht geladen werden.
-    # https://stackoverflow.com/a/43523497/4061870
-    # During weekends there are no updates.
-    # To develop i need a testresource.
-    # In that case i comment the Online Resource block and uncomment the
-    # development Block...
-
-    # ~~~~~~~~~~~~~~~~~~~~~
-    # Online Resource block:
-    # ~~~~~~~~~~~~~~~~~~~~~
-    today = datetime.now().strftime("%Y-%m-%d")
-    SNB_URL = 'https://www.snb.ch/selector/de/mmr/exfeed/rss'
     urlsocket = ''
     try:
-        urlsocket = urllib.request.urlopen(SNB_URL)
+        urlsocket = urllib.request.urlopen(url)
+        return(urlsocket)
     except urllib.error.URLError as e:
         print('err: urllib.request.urlopen: ', e.reason)
+
+
+def parse_rss(urlsocket):
     if urlsocket:
         root = ET.parse(urlsocket)
-        root = ET.ElementTree(root)
+        rss_tree = ET.ElementTree(root)
-        # ~~~~~~~~~~~~~~~~~~~~~
+    return(rss_tree)
-        # development block:
-        # ~~~~~~~~~~~~~~~~~~~~~
-        # today = "2018-01-08"
-        # try:
-        #     root = ET.ElementTree(file='rss')
-        # except Exception as e:
-        #     print('exchange_rates.py_urlsocket failed %s (
-        #           %s) on date: %s for %s'
-        #           % (e, type(e), root))
-        # ~~~~~~~~~~~~~~~~~~~~~
 
-        # Namespaces
+
-        ns = {'rdf': 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
+def get_exchange_rate(rss_tree, ns):
-              'none': 'http://purl.org/rss/1.0/',
+    # Pathvariables to XML Namespaces with
-              'dc': 'http://purl.org/dc/elements/1.1/',
-              'dcterms': 'http://purl.org/dc/terms/',
-              'cb': 'http://www.cbwiki.net/wiki/index.php/Specification_1.2/'
-              }
-        # Pathvariables to XML Namespaces
     rate_path = 'cb:statistics/cb:exchangeRate/'
     observation_path = 'cb:statistics/cb:exchangeRate/cb:observation/'
-        exchange_rates = {}
+    exchange_rates = []
-        for item in root.findall('none:item', ns):
-            # for eatch item n the list we grab the release date
-            # to evaluate if its fresh data or old:
 
-            # THE CURRENCY DATE:
+    for item in rss_tree.findall('none:item', ns):
         datetime_str = item.find('dc:date', ns).text
-            # convert string to date object:
-            # https://stackoverflow.com/a/12282040/4061870
-            # seams like snb striked the microsecond somewhere
-            # between Nov. and Dez. 2017 so maybe first check
-            # time type is with milliseconds:
         try:
             date = datetime.strptime(''.join(
                          datetime_str.rsplit(':', 1)),
@@ -82,10 +51,6 @@ def get_exchange_rate():
             except Exception as e:
                 print('%s (%s)' % (e, type(e)))
                 continue
-            # Print dates for development:
-            # print("date:", date, "today:", today)
-            # only the values of today are used so check for date in XML:
-            if date == today:
         # now search for the currency exchange rate:
         target_currency = item.find(rate_path +
                                     'cb:targetCurrency', ns).text
@@ -135,10 +100,10 @@ def get_exchange_rate():
         # print("date:", date, " 1 ", target_currency, " costs: ",
         #       CHFvalue, "CHF and 1 ", base_currency, " costs: ",
         #       FOREIGNvalue_round, target_currency)
-                exchange_rates.update(
+        data = [{'date': date,
-                    {target_currency: foreign_value_round})
+                 'currency': target_currency,
+                 'exchangerate': foreign_value_round}]
+        exchange_rates.append(data)
         # Print the Dictionary:
-                # print(exchange_rates)
+    print(exchange_rates)
-            else:
+    return(exchange_rates)
-                continue
-        return(exchange_rates, today)

django/didgeridoo/currencies/templatetags/customfilters.py

@@ -6,6 +6,7 @@ register = template.Library()
 
 @register.filter()
 def boldcoffee(value):
+    # currency_of_customer = request.session['currency']
     return '%s !!gefiltert!!' % value
 
     # excample filter: {{ article.price_in_chf|boldcoffee }}

django/didgeridoo/currencies/views.py

@@ -1,5 +1,5 @@
 from django.shortcuts import render
-import datetime
+from datetime import datetime
 from django.views.generic.edit import UpdateView
 from django.core.urlresolvers import reverse_lazy
 from currencies.models import (ExchangeRate,
@@ -25,48 +25,74 @@ def currency_update(request):
 
 
 def currencies(request):
-    # this function fetches the data from exchange_rates.py
+
-    # evaluates if the values are already stored and
+    """this function fetches the data from swiss national bank
-    # prepares the view all dynamicaly.
+    evaluates if the values are already stored and
-    # It can grow in terms of more Currencies over time automaticaly.
+    prepares a view all dynamicaly.
-    today = ''
+    It can grow in terms of more Currencies over time automaticaly."""
-    raw_data = []
+
+    # Namespaces
+    ns = {'rdf': 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
+          'none': 'http://purl.org/rss/1.0/',
+          'dc': 'http://purl.org/dc/elements/1.1/',
+          'dcterms': 'http://purl.org/dc/terms/',
+          'cb': 'http://www.cbwiki.net/wiki/index.php/Specification_1.2/'
+          }
+    SNB_URL = 'https://www.snb.ch/selector/de/mmr/exfeed/rss'
     try:
-        raw_data, today = exchange_rates.get_exchange_rate()
+        urlsocket = exchange_rates.get_rss(SNB_URL)
     except Exception as e:
-        print('views raw_data: ', raw_data, 'error:', e)  # assert False
+        print('currencies/views get_rss(): ', urlsocket, 'error:', e)
-    message_no = "Already querried today: "
+    try:
+        rss_tree = exchange_rates.parse_rss(urlsocket)
+    except Exception as e:
+        print('currencies/views parse_rss(): ', rss_tree, 'error:', e)
+    try:
+        raw_data = exchange_rates.get_exchange_rate(rss_tree, ns)
+    except Exception as e:
+        print('currencies/views get_exchange_rate(): ', raw_data, 'error:', e)
+
+    today = datetime.now().strftime("%Y-%m-%d")
+
+    message_no = "Already querried: "
+    length_of_message_no = len(message_no)
     message_yes = " Updated successfully: "
+    length_of_message_yes = len(message_yes)
     # raw_data can be empty. In this case skip:
     if raw_data:
-        # if raw_data is not empty iterate over items in it:
+        for one_obj_of_list in raw_data:
-        for currency, rate in raw_data.items():
+            for exchange_rate_of_one_day in one_obj_of_list:
+                date = exchange_rate_of_one_day['date']
+                currency = exchange_rate_of_one_day['currency']
+                exchangerate = exchange_rate_of_one_day['exchangerate']
                 # check for already existing exrates per day and add
                 # to message that its already been saved.
                 if ExchangeRate.objects.filter(
-                    date__date=today,
+                        date__date=date,
                         name__name=currency):
-                message_no += currency + ", "
+                    message_no += currency + ' on ' + date + ", "
                 else:
-                if ExchangeRate_date.objects.filter(date=today)[:1]:
+                    if ExchangeRate_date.objects.filter(date=date)[:1]:
                         # if data and currency is not yet present, save it.
                         try:
                             # A: https://stackoverflow.com/a/27802801/4061870
                             # lustigerweise gibt .values() den value und die id
                             # zurück. Ohne .values() gibts nur den "value"
                             date_dict = ExchangeRate_date.objects.filter(
-                            date=today).values()
+                                date=date).values()
                         except Exception as e:
-                        print('exdate_exists %s (%s) on %s'
+                            print('currencies/views/exdate_exists \
+                                %s (%s) on %s'
                                   % (e, type(e), today))
                     else:
                         try:
                             exdate = ExchangeRate_date.objects.create(
-                            date=today)
+                                date=date)
                             exdate.save()
                         except Exception as e:
-                        print('exdate_not_exists %s (%s) for %s'
+                            print('currencies/views/exdate_not_exists \
-                              % (e, type(e), today))
+                                %s (%s) for %s'
+                                  % (e, type(e), date))
                     if ExchangeRate_name.objects.filter(
                             name=currency)[:1]:
                         # if data and currency is not yet present, save it.
@@ -74,7 +100,8 @@ def currencies(request):
                             name_dict = ExchangeRate_name.objects.filter(
                                 name=currency).values()
                         except Exception as e:
-                        print('exname_exists %s (%s) on %s'
+                            print('currencies/views/exname_exists \
+                                %s (%s) on %s'
                                   % (e, type(e), currency))
                     else:
                         try:
@@ -82,7 +109,8 @@ def currencies(request):
                                 name=currency)
                             exname.save()
                         except Exception as e:
-                        print('exname_not_exists %s (%s) on %s'
+                            print('currencies/views/exname_not_exists \
+                                %s (%s) on %s'
                                   % (e, type(e), currency))
                     try:
                         # save item to where id's match.
@@ -92,15 +120,16 @@ def currencies(request):
                                 name=currency).id,
                             # date_id=date_id,
                             date_id=ExchangeRate_date.objects.get(
-                            date=today).id,
+                                date=date).id,
-                        exchange_rate_to_chf=rate,
+                            exchange_rate_to_chf=exchangerate,
                             )
                         exrate.save()
-                    message_yes += currency + ", "
+                        message_yes += currency + ' on ' + date + ", "
 
                     except Exception as e:
-                    print('exrate_create %s (%s) on %s for %s'
+                        print('currencies/views/exrate_create \
-                          % (e, type(e), currency, today))
+                            %s (%s) on %s for %s'
+                              % (e, type(e), currency, date))
 
     # prepare messages:
     # python can not swap a char insinde a sting so i have
@@ -112,11 +141,12 @@ def currencies(request):
     message_yes = message_yes.replace(",", "!", 1)  # replace f. , with !
     message_yes = message_yes[::-1]  # invert the string back
     # here we evaluate what kind of message is valid:
-    if len(message_no) > 24 and len(message_yes) > 23:
+    if len(message_no) > length_of_message_no\
+            and len(message_yes) > length_of_message_yes:
         message = message_no + message_yes
     elif len(message_no) > 24:
         message = message_no
-    elif len(message_yes) > 23:
+    elif len(message_yes) > 18:
         message = message_yes
     elif datetime.datetime.today().isoweekday() == 6:
         message = """Die Abfrage wurde ohne ergebniss beendet.
@@ -130,8 +160,6 @@ def currencies(request):
         """
     else:
         message = """Die Abfrage wurde ohne ergebniss beendet.
-        Kann es sein dass die SNB aufgrund eines Feiertages
-        geschlossen ist?
         """
     # know we can query our data for presentaton:
     currency_list = ExchangeRate.objects.all()

django/didgeridoo/webshop/templates/webshop/index.html

@@ -22,7 +22,7 @@
           </td>
           <td scope="col">{{ article.category }}</td>
           <td scope="col">{{ article.stock }}</td>
-          <td scope="col">{{ article.price_in_chf|boldcoffee }}</td>
+          <td scope="col">{{ article.price_in_chf }}</td>
         </tr>
       {% endfor %}
     </table>