Working on Pygame and Django

4 years ago · b23a9d08a1
2 changed files with 453 additions and 0 deletions
--- a/README.md
+++ b/README.md
@ -2906,6 +2906,249 @@ simpleaudio.play_buffer(samples_b, 1, 2, F)
 ```
 Pygame
 ------
 ### Example
 #### Runs a simple Mario game:
 ```python
 import collections, enum, itertools, pygame, random, math, dataclasses, random
 D      = enum.Enum('D', 'n e s w')
 P      = collections.namedtuple('P', 'x y')
 Mario  = dataclasses.make_dataclass('Mario', ['rect', 'spd', 'facing_left', 'running_cycle'])
 RECT_SIDE, SCR_SIDE, MAX_SPEED = 16, 25, P(x=5, y=10)
 COORDS = [p for p in itertools.product(range(SCR_SIDE), repeat=2) if {*p} & {0, SCR_SIDE-1}] +\
         [(random.randint(1, SCR_SIDE-2), random.randint(2, SCR_SIDE-2)) for _ in range(62)]
 FLOORS = [pygame.Rect(x*RECT_SIDE, y*RECT_SIDE, RECT_SIDE, RECT_SIDE) for x, y in COORDS]
 IMAGE  = pygame.image.load('mario_bros.png')
 FRAMES = [IMAGE.subsurface(pygame.Rect(x*16, 0, 16, 16)) for x in range(7)]
 FRAMES += [pygame.transform.flip(f, True, False) for f in FRAMES]
 def main():
    pygame.init()
    screen = pygame.display.set_mode(2 * [SCR_SIDE*RECT_SIDE])
    mario = Mario(pygame.Rect(16, 16, 16, 16), P(0, 0), False, itertools.cycle(range(3)))
    while not any(event.type == pygame.QUIT for event in pygame.event.get()):
        keys = {pygame.K_UP: D.n, pygame.K_RIGHT: D.e, pygame.K_DOWN: D.s, pygame.K_LEFT: D.w}
        pressed = {keys.get(i, None) for i, on in enumerate(pygame.key.get_pressed()) if on}
        update_speed(mario, pressed)
        update_position(mario)
        draw(screen, mario, pressed)
        pygame.time.wait(28)
 def update_speed(mario, pressed):
    bounds = get_boundaries(mario.rect)
    x, y = mario.spd
    x += 2 * ((D.e in pressed) - (D.w in pressed))
    x = math.copysign(abs(x) - 1, x) if x else 0
    y += 1 if D.s not in bounds else (-10 if D.n in pressed else 0)
    speed = stop_on_collision(P(x, y), bounds)
    mario.spd = P(*[max(-thresh, min(thresh, s)) for thresh, s in zip(MAX_SPEED, speed)])
 def update_position(mario):
    larger_speed = max(abs(s) for s in mario.spd)
    if larger_speed == 0:
        return
    delta, old_p = P(0, 0), mario.rect.topleft
    for _ in range(int(larger_speed)):
        mario.spd = stop_on_collision(mario.spd, get_boundaries(mario.rect))
        delta = P(*[s/larger_speed + dlt for s, dlt in zip(mario.spd, delta)])
        mario.rect.topleft = [sum(a) for a in zip(old_p, delta)]
 def get_boundaries(rect):
    deltas = {D.n: (0, -1), D.e: (1, 0), D.s: (0, 1), D.w: (-1, 0)}
    return {d for d, delta in deltas.items() if rect.move(delta).collidelist(FLOORS) != -1}
 def stop_on_collision(spd, bounds):
    return P(x=0 if (D.w in bounds and spd.x < 0) or (D.e in bounds and spd.x > 0) else spd.x,
             y=0 if (D.n in bounds and spd.y < 0) or (D.s in bounds and spd.y > 0) else spd.y)
 def draw(screen, mario, pressed):
    screen.fill((0, 0, 0))
    mario.facing_left = mario.spd.x < 0 if mario.spd.x else mario.facing_left
    screen.blit(FRAMES[get_frame_index(mario, pressed) + mario.facing_left*7], mario.rect)
    for rect in FLOORS:
        pygame.draw.rect(screen, (255, 100, 0), rect)
    pygame.display.flip()
 def get_frame_index(mario, pressed):
    if D.s not in get_boundaries(mario.rect):
        return 4
    return next(mario.running_cycle) if {D.w, D.e} & pressed else 6
 if __name__ == '__main__':
    main()
 ```
 Django
 ------
 ```bash
 $ pip3 install Django
 $ django-admin startproject mysite
 ```
 ```bash
 $ python3 manage.py startapp polls         # http://localhost:8000/polls/
 $ python3 manage.py migrate
 $ python3 manage.py makemigrations polls
 $ python3 manage.py sqlmigrate polls 0001
 $ python3 manage.py migrate
 $ python3 manage.py shell
 $ python3 manage.py createsuperuser
 $ python3 manage.py runserver              # http://127.0.0.1:8000/admin/
 $ python3 manage.py runserver              # Runs sever internally on port 8000.
 $ python3 manage.py runserver <port>       # Runs sever internally.
 $ python3 manage.py runserver 0:<port>     # Runs server externally.
 ```
 ### Files
 ```text
 mysite/
    mysite/
        settings.py
        urls.py
    polls/
        admin.py
        models.py
        urls.py
        views.py
        templates/
            polls/
                detail.html
                index.html
                results.html
 ```
 #### mysite/mysite/settings.py
 ```python
 INSTALLED_APPS = [
    'polls.apps.PollsConfig',
    ...
 ```
 #### mysite/mysite/urls.py
 ```python
 urlpatterns = [
    url(r'^polls/', include('polls.urls')),
    url(r'^admin/', admin.site.urls),
 ]
 ```
 #### mysite/polls/admin.py
 ```python
 from django.contrib import admin
 from .models import Question
 admin.site.register(Question)
 ```
 #### mysite/polls/models.py
 ```python
 from django.db import models
 class Question(models.Model):
    text     = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')
 class Choice(models.Model):
    question = models.ForeignKey(Question, on_delete=models.CASCADE)
    text     = models.CharField(max_length=200)
    votes    = models.IntegerField(default=0)
 ```
 #### mysite/polls/urls.py
 ```python
 from django.conf.urls import url
 from . import views
 app_name = 'polls'
 urlpatterns = [
    url(r'^$', views.IndexView.as_view(), name='index'),
    url(r'^(?P<pk>[0-9]+)/$', views.DetailView.as_view(), name='detail'),
    url(r'^(?P<pk>[0-9]+)/results/$', views.ResultsView.as_view(), name='results'),
    url(r'^(?P<question_id>[0-9]+)/vote/$', views.vote, name='vote'),
 ]
 ```
 #### mysite/polls/views.py
 ```python
 from django.shortcuts import get_object_or_404, render
 from django.http import HttpResponseRedirect
 from django.urls import reverse
 from django.views import generic
 from .models import Choice, Question
 class IndexView(generic.ListView):
    template_name       = 'polls/index.html'
    context_object_name = 'latest_question_list'
    def get_queryset(self):
        return Question.objects.order_by('-pub_date')[:5]
 class DetailView(generic.DetailView):
    model         = Question
    template_name = 'polls/detail.html'
 class ResultsView(generic.DetailView):
    model         = Question
    template_name = 'polls/results.html'
 def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        data = {'question': question, 'error_message': "You didn't select a choice."}
        return render(request, 'polls/detail.html', data)
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))
 ```
 #### mysite/polls/templates/polls/index.html
 ```html
 {% if latest_question_list %}
    <ul>
    {% for question in latest_question_list %}
        <li><a href="{% url 'polls:detail' question.id %}">{{ question.text }}</a></li>
    {% endfor %}
    </ul>
 {% else %}
    <p>No polls are available.</p>
 {% endif %}
 ```
 #### mysite/polls/templates/polls/detail.html
 ```html
 <h1>{{ question.text }}</h1>
 {% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}
 <form action="{% url 'polls:vote' question.id %}" method="post">
 {% csrf_token %}
 {% for choice in question.choice_set.all %}
    <input type="radio" name="choice" id="choice{{ forloop.counter }}" 
        value="{{ choice.id }}"/>
    <label for="choice{{ forloop.counter }}">{{ choice.text }}</label><br/>
 {% endfor %}
 <input type="submit" value="Vote" />
 </form>
 ```
 #### mysite/polls/templates/polls/results.html
 ```html
 <h1>{{ question.text }}</h1>
 <ul>
 {% for choice in question.choice_set.all %}
    <li>{{ choice.text }} -- {{ choice.votes }} vote{{ choice.votes|pluralize }}</li>
 {% endfor %}
 </ul>
 <a href="{% url 'polls:detail' question.id %}">Vote again?</a>
 ```
 Basic Script Template
 ---------------------
 ```python
--- a/index.html
+++ b/index.html
@ -2474,6 +2474,216 @@ simpleaudio.play_buffer(samples_b, <span class="hljs-number">1</span>, <span cla
 </code></pre></div></div>
 <div><h2 id="pygame"><a href="#pygame" name="pygame">#</a>Pygame</h2><div><h3 id="example-3">Example</h3><div><h4 id="runsasimplemariogame">Runs a simple Mario game:</h4><pre><code class="python language-python hljs"><span class="hljs-keyword">import</span> collections, enum, itertools, pygame, random, math, dataclasses, random
 D      = enum.Enum(<span class="hljs-string">'D'</span>, <span class="hljs-string">'n e s w'</span>)
 P      = collections.namedtuple(<span class="hljs-string">'P'</span>, <span class="hljs-string">'x y'</span>)
 Mario  = dataclasses.make_dataclass(<span class="hljs-string">'Mario'</span>, [<span class="hljs-string">'rect'</span>, <span class="hljs-string">'spd'</span>, <span class="hljs-string">'facing_left'</span>, <span class="hljs-string">'running_cycle'</span>])
 RECT_SIDE, SCR_SIDE, MAX_SPEED = <span class="hljs-number">16</span>, <span class="hljs-number">25</span>, P(x=<span class="hljs-number">5</span>, y=<span class="hljs-number">10</span>)
 COORDS = [p <span class="hljs-keyword">for</span> p <span class="hljs-keyword">in</span> itertools.product(range(SCR_SIDE), repeat=<span class="hljs-number">2</span>) <span class="hljs-keyword">if</span> {*p} &amp; {<span class="hljs-number">0</span>, SCR_SIDE<span class="hljs-number">-1</span>}] +\
         [(random.randint(<span class="hljs-number">1</span>, SCR_SIDE<span class="hljs-number">-2</span>), random.randint(<span class="hljs-number">2</span>, SCR_SIDE<span class="hljs-number">-2</span>)) <span class="hljs-keyword">for</span> _ <span class="hljs-keyword">in</span> range(<span class="hljs-number">62</span>)]
 FLOORS = [pygame.Rect(x*RECT_SIDE, y*RECT_SIDE, RECT_SIDE, RECT_SIDE) <span class="hljs-keyword">for</span> x, y <span class="hljs-keyword">in</span> COORDS]
 IMAGE  = pygame.image.load(<span class="hljs-string">'mario_bros.png'</span>)
 FRAMES = [IMAGE.subsurface(pygame.Rect(x*<span class="hljs-number">16</span>, <span class="hljs-number">0</span>, <span class="hljs-number">16</span>, <span class="hljs-number">16</span>)) <span class="hljs-keyword">for</span> x <span class="hljs-keyword">in</span> range(<span class="hljs-number">7</span>)]
 FRAMES += [pygame.transform.flip(f, <span class="hljs-keyword">True</span>, <span class="hljs-keyword">False</span>) <span class="hljs-keyword">for</span> f <span class="hljs-keyword">in</span> FRAMES]
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">main</span><span class="hljs-params">()</span>:</span>
    pygame.init()
    screen = pygame.display.set_mode(<span class="hljs-number">2</span> * [SCR_SIDE*RECT_SIDE])
    mario = Mario(pygame.Rect(<span class="hljs-number">16</span>, <span class="hljs-number">16</span>, <span class="hljs-number">16</span>, <span class="hljs-number">16</span>), P(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>), <span class="hljs-keyword">False</span>, itertools.cycle(range(<span class="hljs-number">3</span>)))
    <span class="hljs-keyword">while</span> <span class="hljs-keyword">not</span> any(event.type == pygame.QUIT <span class="hljs-keyword">for</span> event <span class="hljs-keyword">in</span> pygame.event.get()):
        keys = {pygame.K_UP: D.n, pygame.K_RIGHT: D.e, pygame.K_DOWN: D.s, pygame.K_LEFT: D.w}
        pressed = {keys.get(i, <span class="hljs-keyword">None</span>) <span class="hljs-keyword">for</span> i, on <span class="hljs-keyword">in</span> enumerate(pygame.key.get_pressed()) <span class="hljs-keyword">if</span> on}
        update_speed(mario, pressed)
        update_position(mario)
        draw(screen, mario, pressed)
        pygame.time.wait(<span class="hljs-number">28</span>)
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">update_speed</span><span class="hljs-params">(mario, pressed)</span>:</span>
    bounds = get_boundaries(mario.rect)
    x, y = mario.spd
    x += <span class="hljs-number">2</span> * ((D.e <span class="hljs-keyword">in</span> pressed) - (D.w <span class="hljs-keyword">in</span> pressed))
    x = math.copysign(abs(x) - <span class="hljs-number">1</span>, x) <span class="hljs-keyword">if</span> x <span class="hljs-keyword">else</span> <span class="hljs-number">0</span>
    y += <span class="hljs-number">1</span> <span class="hljs-keyword">if</span> D.s <span class="hljs-keyword">not</span> <span class="hljs-keyword">in</span> bounds <span class="hljs-keyword">else</span> (<span class="hljs-number">-10</span> <span class="hljs-keyword">if</span> D.n <span class="hljs-keyword">in</span> pressed <span class="hljs-keyword">else</span> <span class="hljs-number">0</span>)
    speed = stop_on_collision(P(x, y), bounds)
    mario.spd = P(*[max(-thresh, min(thresh, s)) <span class="hljs-keyword">for</span> thresh, s <span class="hljs-keyword">in</span> zip(MAX_SPEED, speed)])
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">update_position</span><span class="hljs-params">(mario)</span>:</span>
    larger_speed = max(abs(s) <span class="hljs-keyword">for</span> s <span class="hljs-keyword">in</span> mario.spd)
    <span class="hljs-keyword">if</span> larger_speed == <span class="hljs-number">0</span>:
        <span class="hljs-keyword">return</span>
    delta, old_p = P(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>), mario.rect.topleft
    <span class="hljs-keyword">for</span> _ <span class="hljs-keyword">in</span> range(int(larger_speed)):
        mario.spd = stop_on_collision(mario.spd, get_boundaries(mario.rect))
        delta = P(*[s/larger_speed + dlt <span class="hljs-keyword">for</span> s, dlt <span class="hljs-keyword">in</span> zip(mario.spd, delta)])
        mario.rect.topleft = [sum(a) <span class="hljs-keyword">for</span> a <span class="hljs-keyword">in</span> zip(old_p, delta)]
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get_boundaries</span><span class="hljs-params">(rect)</span>:</span>
    deltas = {D.n: (<span class="hljs-number">0</span>, <span class="hljs-number">-1</span>), D.e: (<span class="hljs-number">1</span>, <span class="hljs-number">0</span>), D.s: (<span class="hljs-number">0</span>, <span class="hljs-number">1</span>), D.w: (<span class="hljs-number">-1</span>, <span class="hljs-number">0</span>)}
    <span class="hljs-keyword">return</span> {d <span class="hljs-keyword">for</span> d, delta <span class="hljs-keyword">in</span> deltas.items() <span class="hljs-keyword">if</span> rect.move(delta).collidelist(FLOORS) != <span class="hljs-number">-1</span>}
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">stop_on_collision</span><span class="hljs-params">(spd, bounds)</span>:</span>
    <span class="hljs-keyword">return</span> P(x=<span class="hljs-number">0</span> <span class="hljs-keyword">if</span> (D.w <span class="hljs-keyword">in</span> bounds <span class="hljs-keyword">and</span> spd.x &lt; <span class="hljs-number">0</span>) <span class="hljs-keyword">or</span> (D.e <span class="hljs-keyword">in</span> bounds <span class="hljs-keyword">and</span> spd.x &gt; <span class="hljs-number">0</span>) <span class="hljs-keyword">else</span> spd.x,
             y=<span class="hljs-number">0</span> <span class="hljs-keyword">if</span> (D.n <span class="hljs-keyword">in</span> bounds <span class="hljs-keyword">and</span> spd.y &lt; <span class="hljs-number">0</span>) <span class="hljs-keyword">or</span> (D.s <span class="hljs-keyword">in</span> bounds <span class="hljs-keyword">and</span> spd.y &gt; <span class="hljs-number">0</span>) <span class="hljs-keyword">else</span> spd.y)
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">draw</span><span class="hljs-params">(screen, mario, pressed)</span>:</span>
    screen.fill((<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>))
    mario.facing_left = mario.spd.x &lt; <span class="hljs-number">0</span> <span class="hljs-keyword">if</span> mario.spd.x <span class="hljs-keyword">else</span> mario.facing_left
    screen.blit(FRAMES[get_frame_index(mario, pressed) + mario.facing_left*<span class="hljs-number">7</span>], mario.rect)
    <span class="hljs-keyword">for</span> rect <span class="hljs-keyword">in</span> FLOORS:
        pygame.draw.rect(screen, (<span class="hljs-number">255</span>, <span class="hljs-number">100</span>, <span class="hljs-number">0</span>), rect)
    pygame.display.flip()
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get_frame_index</span><span class="hljs-params">(mario, pressed)</span>:</span>
    <span class="hljs-keyword">if</span> D.s <span class="hljs-keyword">not</span> <span class="hljs-keyword">in</span> get_boundaries(mario.rect):
        <span class="hljs-keyword">return</span> <span class="hljs-number">4</span>
    <span class="hljs-keyword">return</span> next(mario.running_cycle) <span class="hljs-keyword">if</span> {D.w, D.e} &amp; pressed <span class="hljs-keyword">else</span> <span class="hljs-number">6</span>
 <span class="hljs-keyword">if</span> __name__ == <span class="hljs-string">'__main__'</span>:
    main()
 </code></pre></div></div></div>
 <div><h2 id="django"><a href="#django" name="django">#</a>Django</h2><pre><code class="bash language-bash hljs">$ pip3 install Django
 $ django-admin startproject mysite
 </code></pre></div>
 <pre><code class="bash language-bash hljs">$ python3 manage.py startapp polls         <span class="hljs-comment"># http://localhost:8000/polls/</span>
 $ python3 manage.py migrate
 $ python3 manage.py makemigrations polls
 $ python3 manage.py sqlmigrate polls 0001
 $ python3 manage.py migrate
 $ python3 manage.py shell
 $ python3 manage.py createsuperuser
 $ python3 manage.py runserver              <span class="hljs-comment"># http://127.0.0.1:8000/admin/</span>
 $ python3 manage.py runserver              <span class="hljs-comment"># Runs sever internally on port 8000.</span>
 $ python3 manage.py runserver &lt;port&gt;       <span class="hljs-comment"># Runs sever internally.</span>
 $ python3 manage.py runserver 0:&lt;port&gt;     <span class="hljs-comment"># Runs server externally.</span>
 </code></pre>
 <div><h3 id="files">Files</h3><pre><code class="text language-text">mysite/
    mysite/
        settings.py
        urls.py
    polls/
        admin.py
        models.py
        urls.py
        views.py
        templates/
            polls/
                detail.html
                index.html
                results.html
 </code></pre></div>
 <div><h4 id="mysitemysitesettingspy">mysite/mysite/settings.py</h4><pre><code class="python language-python hljs">INSTALLED_APPS = [
    <span class="hljs-string">'polls.apps.PollsConfig'</span>,
    ...
 </code></pre></div>
 <div><h4 id="mysitemysiteurlspy">mysite/mysite/urls.py</h4><pre><code class="python language-python hljs">urlpatterns = [
    url(<span class="hljs-string">r'^polls/'</span>, include(<span class="hljs-string">'polls.urls'</span>)),
    url(<span class="hljs-string">r'^admin/'</span>, admin.site.urls),
 ]
 </code></pre></div>
 <div><h4 id="mysitepollsadminpy">mysite/polls/admin.py</h4><pre><code class="python language-python hljs"><span class="hljs-keyword">from</span> django.contrib <span class="hljs-keyword">import</span> admin
 <span class="hljs-keyword">from</span> .models <span class="hljs-keyword">import</span> Question
 admin.site.register(Question)
 </code></pre></div>
 <div><h4 id="mysitepollsmodelspy">mysite/polls/models.py</h4><pre><code class="python language-python hljs"><span class="hljs-keyword">from</span> django.db <span class="hljs-keyword">import</span> models
 <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Question</span><span class="hljs-params">(models.Model)</span>:</span>
    text     = models.CharField(max_length=<span class="hljs-number">200</span>)
    pub_date = models.DateTimeField(<span class="hljs-string">'date published'</span>)
 <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Choice</span><span class="hljs-params">(models.Model)</span>:</span>
    question = models.ForeignKey(Question, on_delete=models.CASCADE)
    text     = models.CharField(max_length=<span class="hljs-number">200</span>)
    votes    = models.IntegerField(default=<span class="hljs-number">0</span>)
 </code></pre></div>
 <div><h4 id="mysitepollsurlspy">mysite/polls/urls.py</h4><pre><code class="python language-python hljs"><span class="hljs-keyword">from</span> django.conf.urls <span class="hljs-keyword">import</span> url
 <span class="hljs-keyword">from</span> . <span class="hljs-keyword">import</span> views
 app_name = <span class="hljs-string">'polls'</span>
 urlpatterns = [
    url(<span class="hljs-string">r'^$'</span>, views.IndexView.as_view(), name=<span class="hljs-string">'index'</span>),
    url(<span class="hljs-string">r'^(?P&lt;pk&gt;[0-9]+)/$'</span>, views.DetailView.as_view(), name=<span class="hljs-string">'detail'</span>),
    url(<span class="hljs-string">r'^(?P&lt;pk&gt;[0-9]+)/results/$'</span>, views.ResultsView.as_view(), name=<span class="hljs-string">'results'</span>),
    url(<span class="hljs-string">r'^(?P&lt;question_id&gt;[0-9]+)/vote/$'</span>, views.vote, name=<span class="hljs-string">'vote'</span>),
 ]
 </code></pre></div>
 <div><h4 id="mysitepollsviewspy">mysite/polls/views.py</h4><pre><code class="python language-python hljs"><span class="hljs-keyword">from</span> django.shortcuts <span class="hljs-keyword">import</span> get_object_or_404, render
 <span class="hljs-keyword">from</span> django.http <span class="hljs-keyword">import</span> HttpResponseRedirect
 <span class="hljs-keyword">from</span> django.urls <span class="hljs-keyword">import</span> reverse
 <span class="hljs-keyword">from</span> django.views <span class="hljs-keyword">import</span> generic
 <span class="hljs-keyword">from</span> .models <span class="hljs-keyword">import</span> Choice, Question
 <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">IndexView</span><span class="hljs-params">(generic.ListView)</span>:</span>
    template_name       = <span class="hljs-string">'polls/index.html'</span>
    context_object_name = <span class="hljs-string">'latest_question_list'</span>
    <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">get_queryset</span><span class="hljs-params">(self)</span>:</span>
        <span class="hljs-keyword">return</span> Question.objects.order_by(<span class="hljs-string">'-pub_date'</span>)[:<span class="hljs-number">5</span>]
 <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">DetailView</span><span class="hljs-params">(generic.DetailView)</span>:</span>
    model         = Question
    template_name = <span class="hljs-string">'polls/detail.html'</span>
 <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">ResultsView</span><span class="hljs-params">(generic.DetailView)</span>:</span>
    model         = Question
    template_name = <span class="hljs-string">'polls/results.html'</span>
 <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">vote</span><span class="hljs-params">(request, question_id)</span>:</span>
    question = get_object_or_404(Question, pk=question_id)
    <span class="hljs-keyword">try</span>:
        selected_choice = question.choice_set.get(pk=request.POST[<span class="hljs-string">'choice'</span>])
    <span class="hljs-keyword">except</span> (KeyError, Choice.DoesNotExist):
        data = {<span class="hljs-string">'question'</span>: question, <span class="hljs-string">'error_message'</span>: <span class="hljs-string">"You didn't select a choice."</span>}
        <span class="hljs-keyword">return</span> render(request, <span class="hljs-string">'polls/detail.html'</span>, data)
    <span class="hljs-keyword">else</span>:
        selected_choice.votes += <span class="hljs-number">1</span>
        selected_choice.save()
        <span class="hljs-keyword">return</span> HttpResponseRedirect(reverse(<span class="hljs-string">'polls:results'</span>, args=(question.id,)))
 </code></pre></div>
 <div><h4 id="mysitepollstemplatespollsindexhtml">mysite/polls/templates/polls/index.html</h4><pre><code class="html language-html python hljs xml">{% if latest_question_list %}
    <span class="hljs-tag">&lt;<span class="hljs-name">ul</span>&gt;</span>
    {% for question in latest_question_list %}
        <span class="hljs-tag">&lt;<span class="hljs-name">li</span>&gt;</span><span class="hljs-tag">&lt;<span class="hljs-name">a</span> <span class="hljs-attr">href</span>=<span class="hljs-string">"{% url 'polls:detail' question.id %}"</span>&gt;</span>{{ question.text }}<span class="hljs-tag">&lt;/<span class="hljs-name">a</span>&gt;</span><span class="hljs-tag">&lt;/<span class="hljs-name">li</span>&gt;</span>
    {% endfor %}
    <span class="hljs-tag">&lt;/<span class="hljs-name">ul</span>&gt;</span>
 {% else %}
    <span class="hljs-tag">&lt;<span class="hljs-name">p</span>&gt;</span>No polls are available.<span class="hljs-tag">&lt;/<span class="hljs-name">p</span>&gt;</span>
 {% endif %}
 </code></pre></div>
 <div><h4 id="mysitepollstemplatespollsdetailhtml">mysite/polls/templates/polls/detail.html</h4><pre><code class="html language-html python hljs xml"><span class="hljs-tag">&lt;<span class="hljs-name">h1</span>&gt;</span>{{ question.text }}<span class="hljs-tag">&lt;/<span class="hljs-name">h1</span>&gt;</span>
 {% if error_message %}<span class="hljs-tag">&lt;<span class="hljs-name">p</span>&gt;</span><span class="hljs-tag">&lt;<span class="hljs-name">strong</span>&gt;</span>{{ error_message }}<span class="hljs-tag">&lt;/<span class="hljs-name">strong</span>&gt;</span><span class="hljs-tag">&lt;/<span class="hljs-name">p</span>&gt;</span>{% endif %}
 <span class="hljs-tag">&lt;<span class="hljs-name">form</span> <span class="hljs-attr">action</span>=<span class="hljs-string">"{% url 'polls:vote' question.id %}"</span> <span class="hljs-attr">method</span>=<span class="hljs-string">"post"</span>&gt;</span>
 {% csrf_token %}
 {% for choice in question.choice_set.all %}
    <span class="hljs-tag">&lt;<span class="hljs-name">input</span> <span class="hljs-attr">type</span>=<span class="hljs-string">"radio"</span> <span class="hljs-attr">name</span>=<span class="hljs-string">"choice"</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"choice{{ forloop.counter }}"</span> 
        <span class="hljs-attr">value</span>=<span class="hljs-string">"{{ choice.id }}"</span>/&gt;</span>
    <span class="hljs-tag">&lt;<span class="hljs-name">label</span> <span class="hljs-attr">for</span>=<span class="hljs-string">"choice{{ forloop.counter }}"</span>&gt;</span>{{ choice.text }}<span class="hljs-tag">&lt;/<span class="hljs-name">label</span>&gt;</span><span class="hljs-tag">&lt;<span class="hljs-name">br</span>/&gt;</span>
 {% endfor %}
 <span class="hljs-tag">&lt;<span class="hljs-name">input</span> <span class="hljs-attr">type</span>=<span class="hljs-string">"submit"</span> <span class="hljs-attr">value</span>=<span class="hljs-string">"Vote"</span> /&gt;</span>
 <span class="hljs-tag">&lt;/<span class="hljs-name">form</span>&gt;</span>
 </code></pre></div>
 <div><h4 id="mysitepollstemplatespollsresultshtml">mysite/polls/templates/polls/results.html</h4><pre><code class="html language-html python hljs xml"><span class="hljs-tag">&lt;<span class="hljs-name">h1</span>&gt;</span>{{ question.text }}<span class="hljs-tag">&lt;/<span class="hljs-name">h1</span>&gt;</span>
 <span class="hljs-tag">&lt;<span class="hljs-name">ul</span>&gt;</span>
 {% for choice in question.choice_set.all %}
    <span class="hljs-tag">&lt;<span class="hljs-name">li</span>&gt;</span>{{ choice.text }} -- {{ choice.votes }} vote{{ choice.votes|pluralize }}<span class="hljs-tag">&lt;/<span class="hljs-name">li</span>&gt;</span>
 {% endfor %}
 <span class="hljs-tag">&lt;/<span class="hljs-name">ul</span>&gt;</span>
 <span class="hljs-tag">&lt;<span class="hljs-name">a</span> <span class="hljs-attr">href</span>=<span class="hljs-string">"{% url 'polls:detail' question.id %}"</span>&gt;</span>Vote again?<span class="hljs-tag">&lt;/<span class="hljs-name">a</span>&gt;</span>
 </code></pre></div>
 <div><h2 id="basicscripttemplate"><a href="#basicscripttemplate" name="basicscripttemplate">#</a>Basic Script Template</h2><pre><code class="python language-python hljs"><span class="hljs-comment">#!/usr/bin/env python3</span>
 <span class="hljs-comment">#</span>
 <span class="hljs-comment"># Usage: .py</span>