Eroman: Add lecture 4

2017-03-02T03:33:42Z

Add lecture 4

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== Exceptions ==

this is a good overview:

https://docs.python.org/3/tutorial/errors.html

== Slices ==

== TASK 1 ==

print out bitcoin price in console for EUR.

=== Example output ===

<pre>1064.4876</pre>
=== install requests ===

<pre>pip3 install requests</pre>
=== use requests ===

<source lang="python">import requests

# make an HTTP GET request, and assign 'r' to response object
r = requests.get(my_url)

# convert response to python types, if response is JSON, and assign to 'data'
data = r.json()</source>
<source lang="python">my_dict = {'bpi': []}
# access value for key 'bpi'
my_dict['bpi']
print(my_dict['bpi'])</source>
== MAKE A WEBSITE ==

* Django
* Flask
* Bottle
* Falcon

<pre class="shell">pip3 install django
python3 -m django startproject first_website
cd first_website/first_website
touch views.py

cd ../ # go back to the original first website dir
python3 manage.py runserver</pre>
Add a view<br />
<code>first_website/first_website/view.py</code>

<source lang="python">from django.http import HttpResponse

def my_view(request):
return HttpResponse('hi')</source>
Add the view to the urls<br />
<code>first_website/first_website/view.py</code>

<source lang="python">from first_website.views import my_view

urlpatterns = [
url(r'^admin/', admin.site.urls),
url('$', my_view)
]</source>
=== Running an interactive shell with django ===

<code>python3 manage.py shell</code><br />
get a nicer shell<br />
<code>pip3 install ipython</code>

=== Query string ===

<code>http://google.com/?q=1</code>

the query string is converted to a dictionary like object available as the property <code>GET</code> of the <code>request</code> object

== Task 2 ==

Make a page that gives the bitcoin price in euros

=== Solution ===

<source lang="python">import requests

from django.http import HttpResponse

def my_view(request):
# NOTE: requests with an 's' is the library
r = requests.get('https://api.coindesk.com/v1/bpi/currentprice.json')
data = r.json()
price = data['bpi']['EUR']['rate']
response = HttpResponse(price)
return response</source>

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Eroman: Add lecture 4