Decimal patch

.gitignore

@@ -11,3 +11,4 @@ coverage
 .vagrant
 manifests/build
 *.db
+venv

exchange/adapters/__init__.py

@@ -42,6 +42,9 @@ def update(self):
                                                   target.code,
                                                   usd_exchange_rates)
 
+                if rate == False:
+                    continue
+
                 exchange_rate = ExchangeRate(source=source,
                                              target=target,
                                              rate=rate)
@@ -66,10 +69,25 @@ def update(self):
     def _get_rate_through_usd(self, source, target, usd_rates):
         # from: https://openexchangerates.org/documentation#how-to-use
         # gbp_hkd = usd_hkd * (1 / usd_gbp)
-        usd_source = usd_rates[source]
-        usd_target = usd_rates[target]
+        error = False
+
+        try:
+            usd_source = usd_rates[source]
+        except KeyError:
+            Currency.objects.filter(code=source).delete()
+            error = True
+
+        try:
+            usd_target = usd_rates[target]
+        except KeyError:
+            Currency.objects.filter(code=target).delete()
+            error = True
+
+        if error:
+            return False
+
         rate = usd_target * (Decimal(1.0) / usd_source)
-        rate = rate.quantize(Decimal('0.123456'))  # round to 6 decimal places
+        rate = rate.quantize(Decimal('0.12345678'))  # round to 8 decimal places
         return rate
 
     def get_currencies(self):

exchange/cache.py

@@ -1,4 +1,4 @@
-from django.core.cache import get_cache
+from django.core.cache import caches
 from django.conf import settings
 
 from exchange.models import ExchangeRate
@@ -20,7 +20,7 @@
 
 CACHE_TIMEOUT = 0  # Not configurable at all
 
-cache = get_cache(CACHE_DATABASE)
+cache = caches[CACHE_DATABASE]
 
 
 def _get_cache_key(source_currency, target_currency):

exchange/migrations/0001_initial.py

@@ -1,53 +1,37 @@
 # -*- coding: utf-8 -*-
-import datetime
-from south.db import db
-from south.v2 import SchemaMigration
-from django.db import models
-
-
-class Migration(SchemaMigration):
-
-    def forwards(self, orm):
-        # Adding model 'Currency'
-        db.create_table(u'exchange_currency', (
-            (u'id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
-            ('code', self.gf('django.db.models.fields.CharField')(unique=True, max_length=3)),
-            ('name', self.gf('django.db.models.fields.CharField')(max_length=64)),
-        ))
-        db.send_create_signal(u'exchange', ['Currency'])
-
-        # Adding model 'ExchangeRate'
-        db.create_table(u'exchange_exchangerate', (
-            (u'id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
-            ('source', self.gf('django.db.models.fields.related.ForeignKey')(related_name='rates', to=orm['exchange.Currency'])),
-            ('target', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['exchange.Currency'])),
-            ('rate', self.gf('django.db.models.fields.DecimalField')(max_digits=12, decimal_places=2)),
-        ))
-        db.send_create_signal(u'exchange', ['ExchangeRate'])
-
-
-    def backwards(self, orm):
-        # Deleting model 'Currency'
-        db.delete_table(u'exchange_currency')
-
-        # Deleting model 'ExchangeRate'
-        db.delete_table(u'exchange_exchangerate')
-
-
-    models = {
-        u'exchange.currency': {
-            'Meta': {'object_name': 'Currency'},
-            'code': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '3'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'name': ('django.db.models.fields.CharField', [], {'max_length': '64'})
-        },
-        u'exchange.exchangerate': {
-            'Meta': {'object_name': 'ExchangeRate'},
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'rate': ('django.db.models.fields.DecimalField', [], {'max_digits': '12', 'decimal_places': '2'}),
-            'source': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'rates'", 'to': u"orm['exchange.Currency']"}),
-            'target': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['exchange.Currency']"})
-        }
-    }
-
-    complete_apps = ['exchange']
+# Generated by Django 1.9.5 on 2016-04-06 09:33
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Currency',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('code', models.CharField(max_length=3, unique=True)),
+                ('name', models.CharField(max_length=64)),
+            ],
+            options={
+                'verbose_name_plural': 'currencies',
+            },
+        ),
+        migrations.CreateModel(
+            name='ExchangeRate',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('rate', models.DecimalField(decimal_places=8, max_digits=17)),
+                ('source', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='rates', to='exchange.Currency')),
+                ('target', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='exchange.Currency')),
+            ],
+        ),
+    ]

exchange/migrations/0002_auto_20180802_1451.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.15 on 2018-08-02 14:51
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('exchange', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='exchangerate',
+            name='rate',
+            field=models.DecimalField(decimal_places=8, max_digits=20),
+        ),
+    ]

exchange/models.py

@@ -22,7 +22,7 @@ class ExchangeRate(models.Model):
     """Model to persist exchange rates between currencies"""
     source = models.ForeignKey('exchange.Currency', related_name='rates')
     target = models.ForeignKey('exchange.Currency')
-    rate = models.DecimalField(max_digits=17, decimal_places=8)
+    rate = models.DecimalField(max_digits=20, decimal_places=8)
 
     objects = ExchangeRateManager()
 

exchange/utils.py

@@ -17,7 +17,7 @@ def import_class(class_path):
     'OrderedDict'
     """
     try:
-        from django.utils.importlib import import_module
+        from importlib import import_module
         module_name = '.'.join(class_path.split(".")[:-1])
         mod = import_module(module_name)
         return getattr(mod, class_path.split(".")[-1])
@@ -52,9 +52,18 @@ def insert_many(objects, using="default"):
     table = model._meta.db_table
     column_names = ",".join(con.ops.quote_name(f.column) for f in fields)
     placeholders = ",".join(("%s",) * len(fields))
-    con.cursor().executemany("insert into %s (%s) values (%s)"
-                             % (table, column_names, placeholders), parameters)
-    transaction.commit_unless_managed(using=using)
+
+    from distutils.version import StrictVersion
+    from django import get_version
+    # see https://docs.djangoproject.com/en/1.9/internals/deprecation/#deprecation-removed-in-1-8
+    if StrictVersion(get_version()) >= StrictVersion('1.6.0'):
+        with transaction.atomic():
+            con.cursor().executemany("insert into %s (%s) values (%s)"
+                                    % (table, column_names, placeholders), parameters)
+    else:
+        con.cursor().executemany("insert into %s (%s) values (%s)"
+                                % (table, column_names, placeholders), parameters)
+        transaction.commit_unless_managed(using=using)
 
 
 def update_many(objects, fields=[], using="default"):
@@ -91,11 +100,23 @@ def update_many(objects, fields=[], using="default"):
     table = meta.db_table
     assignments = ",".join(("%s=%%s" % con.ops.quote_name(f.column))
                            for f in fields)
-    con.cursor().executemany("update %s set %s where %s=%%s"
-                             % (table, assignments,
-                                con.ops.quote_name(meta.pk.column)),
-                             parameters)
-    transaction.commit_unless_managed(using=using)
+
+    from distutils.version import StrictVersion
+    from django import get_version
+    # see https://docs.djangoproject.com/en/1.9/internals/deprecation/#deprecation-removed-in-1-8
+    if StrictVersion(get_version()) >= StrictVersion('1.6.0'):
+        with transaction.atomic():
+            con.cursor().executemany("update %s set %s where %s=%%s"
+                                    % (table, assignments,
+                                        con.ops.quote_name(meta.pk.column)),
+                                    parameters)
+    else:
+        con.cursor().executemany("update %s set %s where %s=%%s"
+                                % (table, assignments,
+                                    con.ops.quote_name(meta.pk.column)),
+                                parameters)
+        transaction.commit_unless_managed(using=using)
+
 
 
 def memoize(ttl=None):

test_project/settings.py

@@ -1,4 +1,13 @@
-INSTALLED_APPS = ['exchange']
+DEBUG = True
+
+SECRET_KEY = 'fake-key'
+
+INSTALLED_APPS = [
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'exchange'
+]
 
 DATABASES = {
     'default': {