Developing with Django

class: center, middle

# Developing with Django: 
### Get Your Admin for Nothing<br />and your SQL for Free
<img src="imgs/01/django-logo-negative.png" alt="django" height="70"/>
<img src="imgs/01/python.jpg" alt="python" height="70" style="border:1px solid #ccc;" />

<small>October 2014</small>

---

## today

* ### background
* ### django example
    - ### in: _tabular data_
    - ### out: _database / website_
    
    <img src="imgs/02-background/meth-logo.png" alt="indiana" height="150"/>
    
    
---

## early python: programmers liked it

<br />
<center>
    <table>
        <tr>
            <td><img src="imgs/05-xkcd/python-main.png" alt="xkcd-1.png" width="550" /></td>
            <td><img src="imgs/05-xkcd/python-hello.png" alt="xkcd-2.png" width="200" /></td>
        </tr>
    </table>
</center>
source: [http://xkcd.com/353](http://xkcd.com/353)

---

## web frameworks

<table>
    <tr>
        <td><b>Before 2004/05</b></td>
        <td><b>2005+</b></td>
    </tr>
    <tr>
        <td><img src="imgs/02-background/shovel.png" alt="shovel" width="350" /></td>
        <td><img src="imgs/02-background/plow.png" alt="plow" width="350" /></td>
    </tr>
</table>

---

## python web frameworks

---

## why pay attention?

----
_(heavy python users)_
<div>
    <img src="imgs/06-python-use/dropbox.png" alt="dropbox.png" width="150" />
    <img src="imgs/06-python-use/facebook.jpg" alt="facebook.jpg" width="150" />
    <img src="imgs/06-python-use/google.jpg" alt="google.jpg" width="130" />
    <img src="imgs/06-python-use/figshare.jpg" alt="figshare.jpg" width="180" style="border:4px solid #ff0000;padding:10px;" />
    <img src="imgs/06-python-use/reddit-logo.png" alt="reddit-logo.png" width="130" />
    <img src="imgs/06-python-use/uber_logo.png" alt="uber_logo.png" width="130" />
    <img src="imgs/06-python-use/yelp_logo.png" alt="yelp_logo.png" width="130" />
    <img src="imgs/06-python-use/you_tube.png" alt="you_tube.png" width="130" />
    <img src="imgs/06-python-use/eventbrite-logo.png" alt="eventbrite-logo.png" width="130" />
    <img src="imgs/06-python-use/irobot.png" alt="irobot.png" width="130" />
</div>

----
_(notable django users)_
<center>
    <img src="imgs/06-python-use/instagram.png" alt="instagram.png" width="175" />
    <img src="imgs/06-python-use/pinterest.jpg" alt="pinterest.jpg" width="150" />

---

## strong local interest: python

---

## strong local interest: django

<center>
    <table>
          <tr>
              <td style="vertical-align:top;"><img src="imgs/07-local-interest/meetup-logo.png" alt="meetup" width="75" style="vertical-align:top;" /></td>
              <td style="vertical-align:top;"><img src="imgs/07-local-interest/django1.png" alt="django1" width="275" /></td>
              <td style="vertical-align:top;"><img src="imgs/07-local-interest/django2.png" alt="django2" width="450" /></td>
          </tr>
      </table>
---
## quick note

### - writing correct code is hard<sup>1</sup>
### - reading and reasoning about code is hard<sup>1</sup>
### - it's easier to look at less code<sup>2</sup>

<small><sup>1</sup> <a href="http://www.youtube.com/watch?v=yvjmAYmYOj0">Alex Gaynor SF Python Meetup, July 2014</a></small>
<br /><small><sup>2</sup> 1 FTE depending on public transport 
<table>
    <tr>
        <td>

---
## another note

---

## python glimpse: list (1 of 2)

```python
>>> l = ['cat', 'dog', 7, 'bird', 108]  # define

>>> for x in l: print (x)   # iterate
... 
cat
dog
7
bird
108

>>> l.sort()    # sort
>>> l
[7, 108, 'bird', 'cat', 'dog']

>>> len(x)  # size
5

```

---

## python glimpse: list (2 of 2)

```python
>>> l[0:2], l[-3:]   # slice 1st 2 items and last 3 items 
[7, 108], ['bird', 'cat', 'dog']

>>> filter(lambda x: type(x) is str, l) # remove non-strings
['bird', 'cat', 'dog']

>>> some_strings = [ '  got', 'whitepace   ', ' ?  ']
>>> [ x.strip() for x in some_strings ]     # transform each item
['got', 'whitepace', '?']

>>> import string
>>> '-'.join(string.ascii_uppercase)    # join
'A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z'

```
---

## python glimpse: dictionary (1 of 2)

```python
>>> d = {}      # create a dict  { key : value}

>>> d['greeting'] = 'hello'     # add an item
>>> d['closed_tickets'] = 848     # add an item
>>> d['pets'] = ['dog', 'cat', 'bird']  # and another

>>> d   # unordered
{'closed_tickets': 848, 'greeting': 'hello', 'pets': ['dog', 'cat', 'bird']}

>>> d.get('greeting')
'hello'

>>> d.keys()    # show keys (unordered)
['greeting', 'pets', 'closed_tickets']

```

---

## python glimpse: dictionary (2 of 2)

```python
>>> d.has_key('donut')
False

>>> d.get('bad key', '--no match--')    # default if key not found
'--no match--'

>>> for key, val in d.items():  # iterate through
...     print '%s -> %s' % (key, val)
... 
closed_tickets -> 848
greeting -> hello
pets -> ['dog', 'cat', 'bird']

>>> d.get('bad key', '--no match--')    # default if key not found
'--no match--'
```

---

## django: spreadsheet to database

<center>
    <table>
        <tr>
            <td style="vertical-align:top;"><img src="imgs/10-models/meth_suppression.jpg" height="150" alt="meth_suppression" /></td>
            <td><a href="/Users/rmp553/Documents/iqss-git/indiana-meth-labs/scripts/meth_data/ISP_Meth_Lab_Locations_Table.xls"><img src="imgs/10-models/spreadsheet.png" height="450" alt="spreadsheet.png" /></a></td>
        </tr>
    </table>
</center>

---

## potentially 5 tables

---

## no problem

1. database

2. web admin interface (add/edit/delete)

3. serialization: JSON, XML

4. ORM access:  command line or in files

---

## django: file layout

```unix
methlabs\
    settings\
        base.py
*       local.py        # apps, db type (postgres, sqlite, mysql, etc)

apps\
    counties\
        __init__.py     
        admin.py
        models.py       # define tables
        
    clanlabs\
        __init__.py     
        admin.py
*       models.py       # define tables

share\
        __init__.py     
        admin.py
        models.py       # define tables

```

---
## in the settings file

#### database

```python
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3', # mysql, postgres, etc
        'NAME': normpath(join(TEST_SETUP_DIR, 'methlabs.db3')),
        'USER': '',
        'PASSWORD': '',
        'HOST': '',
        'PORT': '',
    },
   
}
```

#### apps

```python
LOCAL_APPS = (
    'apps.counties',
    'apps.clanlabs',
    'apps.share',
)
```

---

## each table: define model

```python
# from file apps/clanlabs/models.py
from django.db import models

class ManufacturingMethod(models.Model):
    
    name = models.CharField(max_length=100, unique=True)    
    
    description = models.TextField(blank=True)
    
    sort_order = models.IntegerField(default=10)
    
    slug = models.SlugField(blank=True, help_text='auto-filled on save')
    
    
    def __unicode__(self):
        return self.name
    
    class Meta:
        ordering = ('sort_order', 'name', )
```

---

## django models: preview sql

```unix
> python manage.py sqlall clanlabs
```

```sql
CREATE TABLE "clanlabs_manufacturingmethod" (

*   "id" integer NOT NULL PRIMARY KEY,

*   "name" varchar(100) NOT NULL UNIQUE,

"description" text NOT NULL,

"sort_order" integer NOT NULL,

"slug" varchar(50) NOT NULL
)
;
CREATE INDEX "clanlabs_manufacturingmethod_f52cfca0"
  ON "clanlabs_manufacturingmethod" ("slug");

```

---

## django models: run sql

```unix
*> python manage.py syncdb
```

```unix
Creating tables ...
Creating table clanlabs_seizurelocationtype
*Creating table clanlabs_manufacturingmethod
Creating table clanlabs_clandestinelabreport_seizure_location_types
Creating table clanlabs_clandestinelabreport_manufacturing_methods
Creating table clanlabs_clandestinelabreport
Installing custom SQL ...
Installing indexes ...
Installed 11 object(s) from 1 fixture(s)

```

---

## handling FK and M2M

```python
# from file apps/clanlabs/models.py
class ClandestineLabReport(models.Model):
    
    case_number = models.CharField(max_length=255, db_index=True)   
    
    report_date = models.DateField(validators=[validate_report_date])
        
*   town = models.ForeignKey(Town)
    
*   manufacturing_methods = models.ManyToManyField(ManufacturingMethod\
*                            , blank=True, null=True)

# (.. other fields hidden ..)

```
<img src="imgs/10-models/m2m_relation.png" height="280" alt="manufacture" />

---

## django models: preview sql FK

```unix
> python manage.py sqlall clanlabs 
```

```sql
CREATE TABLE "clanlabs_clandestinelabreport" (
    "id" integer NOT NULL PRIMARY KEY,
    "case_number" varchar(255) NOT NULL,
    "report_date" date NOT NULL,
*   "town_id" integer NOT NULL REFERENCES "counties_town" ("id"),
/*  (.. other fields not shown ..) */
);
```

```sql
CREATE INDEX "clanlabs_clandestinelabreport_850831a2" 
    ON "clanlabs_clandestinelabreport" ("town_id");
```
<a href="imgs/10-models/fk-relation.png"><img src="imgs/10-models/fk-relation.png" height="280" alt="fk-relation" /></a>

---

## django models: preview sql M2M

```unix
> python manage.py sqlall clanlabs 
```

```sql
CREATE TABLE "clanlabs_clandestinelabreport_manufacturing_methods" (
    "id" integer NOT NULL PRIMARY KEY,
*   "clandestinelabreport_id" integer NOT NULL,
*    "manufacturingmethod_id" integer NOT NULL REFERENCES "clanlabs_manufacturingmethod" ("id"),
*    UNIQUE ("clandestinelabreport_id", "manufacturingmethod_id")
)
```

```sql
CREATE INDEX "clanlabs_clandestinelabreport_manufacturing_methods_4d8f49ca" ON "clanlabs_clandestinelabreport_manufacturing_methods" ("clandestinelabreport_id");
CREATE INDEX "clanlabs_clandestinelabreport_manufacturing_methods_21911cdd" ON "clanlabs_clandestinelabreport_manufacturing_methods" ("manufacturingmethod_id");
```

---
## django models: M2M table

### created on sync/migrate

```
>python manage.py syncdb
```

```unix
Creating tables ...
Creating table clanlabs_seizurelocationtype
Creating table clanlabs_manufacturingmethod
Creating table clanlabs_clandestinelabreport_seizure_location_types
*Creating table clanlabs_clandestinelabreport_manufacturing_methods
Creating table clanlabs_clandestinelabreport
Installing custom SQL ...
Installing indexes ...
Installed 11 object(s) from 1 fixture(s)
```

---
## checklist

1. <s>database</s>

2. web admin interface (add/edit/delete)

3. serialization: JSON, XML

4. ORM access:  command line or in files
----
### development cost
- 2 files with models
    - [clanlabs models.py - 67 sloc](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/clanlabs/models.py)
    - [counties models.py - 33 sloc](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/counties/models.py)

- Total code: 100 lines

---
##  web admin interface (add/edit/delete)

```unix
apps\
    counties\
        __init__.py     
        admin.py        # define admin
        models.py       # define tables
        
    clanlabs\
        __init__.py     
*       admin.py        # define admin
        models.py       # define tables

share\
        __init__.py     
        admin.py        # define admin
        models.py       # define tables

```
---

##  web admin interface (add/edit/delete)

### one line of code

```python
# apps/clanlabs/admin.py
from django.contrib import admin
*from apps.clanlabs.models import SeizureLocationType

*admin.site.register(SeizureLocationType, SeizureLocationTypeAdmin)
```

<a href="http://127.0.0.1:8000/indiana-methlabs-admin/clanlabs/seizurelocationtypeproxy/" target="_blank">simple admin page</a>

---

##  web admin interface (add/edit/delete)

### few more lines of code

```python
# apps/clanlabs/admin.py
from django.contrib import admin
*from apps.clanlabs.models import SeizureLocationType

class SeizureLocationTypeAdmin(admin.ModelAdmin):
    save_on_top = True
    list_display = ('name', 'sort_order', 'slug' )
    search_fields = ('name',)
    list_editable = ('sort_order',)
    readonly_fields = ('modified', 'created' )
*admin.site.register(SeizureLocationType, SeizureLocationTypeAdmin)

```

<a href="http://127.0.0.1:8000/indiana-methlabs-admin/clanlabs/seizurelocationtype/" target="_blank">admin page 2</a>

<a href="http://127.0.0.1:8000/indiana-methlabs-admin/clanlabs/clandestinelabreport/">admin page - more formatting</a>

---

## checklist

1. <s>database</s>

2. <s>web admin interface (add/edit/delete)</s>
    
3. serialization: JSON, XML

4. ORM access:  command line or in files
----
### development cost
- 2 files with models 
    - 100 sloc (simple )
- 2 files with admins (minutes for minimum)
    - [clanlabs models.py 51 -- but could do 5 sloc](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/clanlabs/admin.py)
    - [counties models.py - 15 sloc](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/counties/admin.py)

- Total code: 166 lines
---
## serialization

#### use your models

```unix
python manage.py shell
```

```python
from apps.clanlabs.models import ClandestineLabReport
from django.core import serializers

queryset = ClandestineLabReport.objects.filter(report_date__year=2014)[0:5]

data = serializers.serialize("json", queryset, indent=4)
print(data)

data = serializers.serialize("xml", queryset, indent=4)
print(data)
```
---

## serialization: dumpdata, loaddata

#### from unix command line
```python
# to JSON
python manage.py dumpdata --indent=4 clanlabs.manufacturingmethod

# to XML
python manage.py dumpdata --indent=4 --format=xml clanlabs.manufacturingmethod

# pipe to file
python manage.py dumpdata --indent=4 clanlabs.seizurelocationtype 
        > apps/clanlabs/fixtures/locations.json

# load from file
python manage.py dumpdata --indent=4 clanlabs.seizurelocationtype 
        > apps/clanlabs/fixtures/locations.json

```

---

## checklist

1. <s>database</s>

2. <s>web admin interface (add/edit/delete)</s>
    
3. <s>serialization: JSON, XML</s>

4. ORM access:  command line or in files
----
### development cost
- 2 files with models

- 2 files with admins (minutes for minimum)

- Free!

- Total code: 166 lines

---

## ORM access

```unix
python manage.py shell
```

```python
from apps.clanlabs.models import SeizureLocationType, ManufacturingMethod, ClandestineLabReport

l = SeizureLocationType.objects.all()
for s in l:
   print s.id, s.name

l.count()

for x in range(1,100):
    s = SeizureLocationType(name=u'loc: %d' % x)
    s.save()

# check admin

bad_locations = SeizureLocationType.objects.filter(name__startswith=u'loc')
bad_locations.delete()
```

[admin](http://127.0.0.1:8000/indiana-methlabs-admin/clanlabs/seizurelocationtype/)

---

## checklist

1. <s>database</s>

2. <s>web admin interface (add/edit/delete)</s>
    
3. <s>serialization: JSON, XML</s>

4. <s>ORM access:  command line or in files</s>

----
### development cost
- 2 files with models 
    
- 2 files with admins (minutes for minimum)

- Free!

- Total code: 166 lines

---
## Show it in the browser

---

## Show it in the browser: URL

1 url 
```python
# urls.py
   
    url(r'^list/august-2014/$', 'view_august_2014', name="view_august_2014"),
    
    #       --actual url--       --function --       --url name (arbitrary)--
    
```

<br />
map to 1 view
```python
# views.py

def view_august_2014(request):
        # return something
```
---

## Show it in the browser: URL

```python
urlpatterns = patterns('apps.clanlabs.views',
    
    
    
    url(r'^list/august-2014/$', 'view_august_2014', name="view_august_2014"),

#       --actual url--       --function --         --url name (arbitrary)--

)
```
[url name in template](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/templates/base.html#L56)

[apps/clanlabs/urls.py](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/clanlabs/urls.py)
---

## Show it in the browser: View

```python
# apps/clanlabs/views.py
def view_august_2014(request):

d = {}  # dict { key : value}
    
    d['title'] = 'August 2014 Report Listing'
    
    # pull reports from the database
    d['reports'] = ClandestineLabReport.objects.filter(is_visible=True\
                                    , report_date__year=2014\
                                    , report_date__month=8)
        
    return render_to_response('labs/view_august_2014.html'\
                            , d\
                            , context_instance=RequestContext(request))

```

<br />
<br />
[apps/clanlabs/views.py](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/clanlabs/views.py)
---

## Show it in the browser: Template

```html
<h1>{{ title }}</h1>

<b>{{ reports.count }}</b> report{{ reports.count|pluralize }} Listed.

<table>
    {% for r in reports %}
        <tr>
            <td>{{ forloop.counter }}</td>
            <td>{{ r.report_date }}</td>
            <td>{{ r.case_number }}</td>
            <td>{{ r.lab_number }}</td>
            <td>{{ r.address }}</td>
            <td>{{ r.county }}</td>
        </tr>
    {% empty %}
        <tr>
            <td>No reports for this month</td>
        </tr>
    {% endfor %}
</table>```

[templates/labs/view_august_2014.html](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/templates/labs/view_august_2014.html) |
<a href="http://127.0.0.1:8000/labs/list/august-2014/" target="_blank">see page</a>

---

## URL Parameters

two urls
```python
    url(r'^list/august-2014/$', 'view_august_2014', name="view_august_2014"),

url(r'^list/(?P<year>[0-9]{4})/(?P<month>[0-9]{1,2})/$'
            , 'view_list_by_month', name="view_list_by_month"),
```

map to two views
```python
    def view_august_2014(request):
        # do something
    
    def view_list_by_month(request, year, month):
        # do something
```

---

## Show it in the browser: More Views

#### The ORM loves me
#### <a href="http://127.0.0.1:8000/labs/list-inefficient/2014/8/" target="_blank">The ORM loves me not</a>

---

## Show it in the browser: Month Menu

#### query

```python
d['month_menu'] =  ClandestineLabReport.objects.filter(is_visible=True\
                                        , report_date__year=year\
                                    ).dates('report_date', 'month')
```

#### template snippet
```html
  <ul class="pagination pagination" style="padding:0;margin:0">
  {% for mm in month_menu %}
      <li{% if mm == selected_month %} class="active"{% endif %}>
*        <a href="{% url 'view_list_by_month_with_menu' mm.year mm.month %}">
            {{ mm|date:"M"}}
        </a>
      </li>
  {% empty %}
      <li>No data available</li>
  {% endfor %}
  </ul>
```
#### <a href="http://127.0.0.1:8000/labs/list-with-menu/2014/8/" target="_blank">page</a>

---

## Share: Make a Form

#### [model](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/share/models.py#L6)
```python
class SharedReportRecord(TimeStampedModel):
    report_month = models.DateField()
    to_email = models.EmailField()
    from_name =  models.CharField(max_length=100)
    from_email = models.EmailField()
    full_message = models.TextField(blank=True)
    md5 = models.CharField(max_length=40, blank=True, db_index=True, help_text='auto-filled on save')
```
#### [form](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/share/forms.py#L1)
```python
class SharedReportRecordForm(forms.ModelForm):
    class Meta:
        model = SharedReportRecord
        widgets = {'report_month': forms.HiddenInput() }
        exclude = ['full_message', 'md5', 'created', 'modified']
```

---

## Share: Display the Form

```python
def view_share_report(request, year, month):
    d = {}

if request.POST:
*       f = SharedReportRecordForm(request.POST)
*       if f.is_valid():
            shared_report_record = f.save()
            email_report(request, shared_report_record)
            success_url = reverse('view_share_report_success'\
                                , kwargs=dict(shared_info_md5=shared_report_record.md5)\
                                )
            return HttpResponseRedirect(success_url)
        else:
            print (f.errors)
            d['ERROR_FOUND']  = True
    else:
*       f = SharedReportRecordForm(initial={ 'report_month' : selected_month })

*   d['share_form'] = f
    return render_to_response('share/share.html', d)
```
[views](https://github.com/raprasad/indiana-meth-labs/blob/master/methlabs/apps/share/views.py#L50)
 | <a href="http://127.0.0.1:8000/share/send-email/2014/8/" target="_blank">share report</a>

---
## Share Form Template

simple
```html
{{ share_form }}
```

more control
```html
{% for field in share_form.visible_fields %}
    <tr>
        <th class="text-primary">{{ field.label_tag }}</th>
        <td>{{ field }}       
            {% if field.errors %}     
            <span class="text-danger">
                 {% for error in field.errors %}
                  <br />{{ field.label_tag }}: {{ error }}
                {% endfor %}
            </span>
            {% endif %}                 
         </td>
    </tr>
{% endfor %}
```

---

## Form: Validation is its own Talk

example of cross field validation

```python
class SharedReportRecordForm(forms.ModelForm):

class Meta:
        model = SharedReportRecord

def clean(self):

from_email = self.cleaned_data.get('from_email')
        to_email = self.cleaned_data.get('to_email')

if from_email and to_email:
            if from_email == to_email:
                msg = 'Why are you sending email to yourself'
                self._errors["to_email"] = self.error_class([msg])

self._errors["from_email"] = self.error_class([msg2])
                msg2 = 'To and From email cannot be the same'

return self.cleaned_data
```

---

## Form validation: another peak

```python
    if request.POST:
*       f = SharedReportRecordForm(request.POST)
*       if f.is_valid():
            print(f)
```

```javascript
{'to_email': u'raman_prasad@harvard.edu', 'from_name': u'raman', 'report_month': datetime.date(2014, 8, 1), 'from_email': u'raprasad@gmail.com'}
```

---
## Send an HTML Email

```python
from django.core.mail import EmailMultiAlternatives

msg = EmailMultiAlternatives(subject, text_content, from_email, [to_email])
msg.attach_alternative(html_content, "text/html")
msg.send()
```
---

## API: Tastypie Example

```html
/api/v1/seizure-location-type/...```

```python
#apps/clanlabs/api.py
*class SeizureLocationTypeResource(ModelResource):
    class Meta:
        queryset = SeizureLocationType.objects.all()
        resource_name = 'seizure-location-type'
        excludes = [ 'created', 'modified']
```

```python
#urls.py
from tastypie.api import Api
*from apps.clanlabs.api import SeizureLocationTypeResource, ClanLabReportResource

v1_api = Api(api_name='v1')
v1_api.register(SeizureLocationTypeResource())
v1_api.register(ClanLabReportResource())

urlpatterns += patterns('',
    (r'^api/', include(v1_api.urls)),   
)```

<a href="http://127.0.0.1:8000/" target="_blank">api example</a>

---

## covered today

### models
- defining tables | serialization | ORM | API

### admin
- defining | web interface

### urls / views / templates
- ORM gotcha: ForeignKey, ManyToMany
- simple form

### <span style="color:#006699;"><i>you can get a lot from models</i></span>
---

## out of time

### reference
- [excellent documentation](https://docs.djangoproject.com) | [many books](http://www.amazon.com/s/ref=sr_kk_1?rh=i%3Astripbooks%2Ck%3Adjango+python&keywords=django+python)

### much, much more built-in
- [db migrations](https://docs.djangoproject.com/en/1.7/topics/migrations/)
| [testing](https://docs.djangoproject.com/en/1.6/topics/testing/overview/)
| [internationalization](https://docs.djangoproject.com/en/1.7/topics/i18n/)
- [caching](https://docs.djangoproject.com/en/1.6/topics/cache/)
| [geo django](https://docs.djangoproject.com/en/1.6/ref/contrib/gis/)
- etc, etc

### popular packages for django
- [haystack: solr, elastic search, whoosh, xapian](http://haystacksearch.org/)
- [nosql, mongo ORM](https://django-mongodb-engine.readthedocs.org/en/latest/index.html)
- [celery task queue: redis, RabbitMQ, etc](http://www.celeryproject.org/)
---
class: center, middle

## thank you

---

## django models: define slug note 1

```python
>>> from django.utils.text import slugify

>>> slugify("1737 Cambridge St")
'1737-cambridge-st'

>>> slugify(u"I Want A Nice Polite URL!#$@")
'i-want-a-nice-polite-url'

```

---

## django models: define slug note 2

```python
*from django.utils.text import slugify
from django.db import models

class ManufacturingMethod(models.Model):
    
    name = models.CharField(max_length=100, unique=True)    
    description = models.TextField(blank=True)
    sort_order = models.IntegerField(default=10)
*   slug = models.SlugField(blank=True, help_text='auto-filled on save')
    
    def __unicode__(self):
        return self.name
        
    def save(self, *args, **kwargs):
*       self.slug = slugify(self.name)
        super(ManufacturingMethod, self).save(*args, **kwargs)
        
    class Meta:
        ordering = ('sort_order', 'name', )
```

???

slugify. lowercase string
  * in: 'This location'
  * out: 'this-location'