Django Paginator

views.py

from django.shortcuts import render_to_response
from django.template import RequestContext
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger

from blog.data.models import Entry

def index(request):
    entries = Entry.objects.published_entries().order_by('-id')
    paginator = Paginator(entries, 2)
    page_num = request.GET.get('page', 1)
    try:
        page = paginator.page(page_num)
    except EmptyPage:
        page = paginator.page(paginator.num_pages)
    except PageNotAnInteger:
        page = paginator.page(1)
    return render_to_response('homepage/index.html', {'page': page}, context_instance = RequestContext(request))

--------------------------------------------------------------------------------------------

index.html

{% extends "homepage/base.html" %}

{% block content %}
    <h3>Entries</h3>
    {% for entry in page.object_list %}
    <div>{{ entry.title }} - {{ entry.created }}</div>
    <div>{{ entry.text }}</div>
    <br />
    {% endfor %}
   
    {% if page.has_previous %}
    <a href="?page={{ page.previous_page_number }}">prev</a>
    {% endif %}
   
    | {{ page.number }} |
   
    {% if page.has_next %}
    <a href="?page={{ page.next_page_number }}">next</a>
    {% endif %}
   
{% endblock %}

Django MEDIA_URL in Templates

settings.py

# Absolute filesystem path to the directory that will hold user-uploaded files.
# Example: "/home/media/media.lawrence.com/media/"
MEDIA_ROOT = os.path.normpath(os.path.join(os.path.dirname(__file__), 'static/'))

# URL that handles the media served from MEDIA_ROOT. Make sure to use a
# trailing slash.
# Examples: "http://media.lawrence.com/media/", "http://example.com/media/"
MEDIA_URL = '/static/'

# Absolute path to the directory static files should be collected to.
# Don't put anything in this directory yourself; store your static files
# in apps' "static/" subdirectories and in STATICFILES_DIRS.
# Example: "/home/media/media.lawrence.com/static/"
STATIC_ROOT = ''

# URL prefix for static files.
# Example: "http://media.lawrence.com/static/"
STATIC_URL = '/static/'

# URL prefix for admin static files -- CSS, JavaScript and images.
# Make sure to use a trailing slash.
# Examples: "http://foo.com/static/admin/", "/static/admin/".
ADMIN_MEDIA_PREFIX = '/static/admin/'

TEMPLATE_CONTEXT_PROCESSOR = (
    'django.contrib.auth.context_processors.auth',
    'django.core.context_processors.media',
)

--------------------------------------------------------------------------------------------

views.py

from django.shortcuts import render_to_response
from blog.data.models import Entry
from django.template import RequestContext

def index(request):
    entries = Entry.objects.published_entries().order_by('-id')
    return render_to_response('homepage/index.html', {'entries': entries}, context_instance = RequestContext(request))

def about(request):
    return render_to_response('homepage/about.html', context_instance = RequestContext(request))

def contact(request):
    return render_to_response('homepage/contact.html', context_instance = RequestContext(request))

def archive(request):
    return render_to_response('homepage/archive.html', context_instance = RequestContext(request))

--------------------------------------------------------------------------------------------

base.html

<html>
<head>
    <title>{% block title %}{% endblock %}</title>
    {% block js %}{% endblock %}
    {% block css %}<link rel="stylesheet" href="{{ MEDIA_URL }}css/main.css" type="text/css" media="screen" />{% endblock %}
</head>
<body>
    <div id="top">My Blog</div>
    <div id="navi">{% block navi %}{% endblock %}</div>
    <div id="content">{% block content %}{% endblock %}</div>
    <div id="footer">{% block footer %}{% endblock %}</div>
</body>
</html>

Django Static files on Developer Server

base.html

<html>
<head>
    <title>{% block title %}{% endblock %}</title>
    {% block js %}{% endblock %}
    {% block css %}<link rel="stylesheet" href="/static/css/main.css" type="text/css" media="screen" />{% endblock %}
</head>
<body>
    <div id="top">My Blog</div>
    <div id="navi">{% block navi %}{% endblock %}</div>
    <div id="content">{% block content %}{% endblock %}</div>
    <div id="footer">{% block footer %}{% endblock %}</div>
</body>
</html>

--------------------------------------------------------------------------------------------

settings.py

# Absolute filesystem path to the directory that will hold user-uploaded files.
# Example: "/home/media/media.lawrence.com/media/"
MEDIA_ROOT = os.path.normpath(os.path.join(os.path.dirname(__file__), 'static/'))

# URL that handles the media served from MEDIA_ROOT. Make sure to use a
# trailing slash.
# Examples: "http://media.lawrence.com/media/", "http://example.com/media/"
MEDIA_URL = '/static/'

# Absolute path to the directory static files should be collected to.
# Don't put anything in this directory yourself; store your static files
# in apps' "static/" subdirectories and in STATICFILES_DIRS.
# Example: "/home/media/media.lawrence.com/static/"
STATIC_ROOT = ''

# URL prefix for static files.
# Example: "http://media.lawrence.com/static/"
STATIC_URL = '/static/'

# URL prefix for admin static files -- CSS, JavaScript and images.
# Make sure to use a trailing slash.
# Examples: "http://foo.com/static/admin/", "/static/admin/".
ADMIN_MEDIA_PREFIX = '/static/admin/'

INSTALLED_APPS = (
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    'django.contrib.messages',
    'django.contrib.admin',
    'blog.data',
)

-------------------------------------------------------------------------------------------- 

urls.py

from django.conf.urls.defaults import patterns, include, url

from blog import settings

from django.contrib import admin
admin.autodiscover()

urlpatterns = patterns('',
    url(r'^$', 'blog.homepage.views.index', name = 'homepage_index'),
    url(r'^about/$', 'blog.homepage.views.about', name = 'homepage_about'),
    url(r'^contact/$', 'blog.homepage.views.contact', name = 'homepage_contact'),
    url(r'^archive/$', 'blog.homepage.views.archive', name = 'homepage_archive'),
    url(r'^admin/', include(admin.site.urls)),
    url(r'^static/(?P<path>.*)$', 'django.views.static.serve', {'document_root': settings.MEDIA_ROOT}),
)

Django Urls from urls.py in Templates

urls.py

from django.conf.urls.defaults import patterns, include, url

from blog import settings

from django.contrib import admin
admin.autodiscover()

urlpatterns = patterns('',
    url(r'^$', 'blog.homepage.views.index', name = 'homepage_index'),
    url(r'^about/$', 'blog.homepage.views.about', name = 'homepage_about'),
    url(r'^contact/$', 'blog.homepage.views.contact', name = 'homepage_contact'),
    url(r'^archive/$', 'blog.homepage.views.archive', name = 'homepage_archive'),
    url(r'^admin/', include(admin.site.urls)),
    url(r'^static/(?P<path>.*)$', 'django.views.static.serve', {'document_root': settings.MEDIA_ROOT}),
)

--------------------------------------------------------------------------------------------

index.html

{% extends "homepage/base.html" %}

{% block title %}My Blog Index{% endblock %}

{% block navi %}
<a href="{% url homepage_index %}">home</a> - <a href="{% url homepage_about %}">about</a> - <a href="{% url homepage_archive %}">archive</a> - <a href="{% url homepage_contact %}">contact</a>
{% endblock %}

{% block content %}
    <h3>Entries</h3>
    {% for entry in entries %}
    <div>{{ entry.title }} - {{ entry.created }}</div>
    <div>{{ entry.text }}</div>
    <br />
    {% endfor %}
{% endblock %}

{% block footer %}
2011 - MyBlog
{% endblock %}

Django Model Managers

data/managers.py

from django.db import models

class EntryManager(models.Manager):
    def published_entries(self):
        return self.model.objects.filter(published = True)

--------------------------------------------------------------------------------------------

data/models.py

#-*- coding: utf-8 -*-

from django.db import models
from blog.data.managers import EntryManager

class Entry(models.Model):
    created = models.DateTimeField(auto_now_add = True)
    updated = models.DateTimeField(auto_now = True)
    title   = models.CharField(max_length = 64)
    text    = models.TextField()
    published = models.BooleanField(db_index = True, default = True)
   
    objects = EntryManager()
   
    def __unicode__(self):
        return u'%s - %s' % (self.title, self.created)

--------------------------------------------------------------------------------------------

data/views.py

from django.shortcuts import render_to_response
from blog.data.models import Entry

def index(request):
    entries = Entry.objects.published_entries().order_by('-id')
    return render_to_response('homepage/index.html', {'entries': entries})

Comparison of Common Windows and Linux Commands

Command's Purpose	MS-DOS	Linux	Basic Linux Example
Copies files	copy	cp	cp thisfile.txt /home/thisdirectory
Moves files	move	mv	mv thisfile.txt /home/thisdirectory
Lists files	dir	ls	ls
Clears screen	cls	clear	clear
Closes prompt window	exit	exit	exit
Displays or sets date	date	date	date
Deletes files	del	rm	rm thisfile.txt
"Echoes" output on the screen	echo	echo	echo this message
Edits files with simple text editor	edit	pico[a]	pico thisfile.txt
Compares the contents of files	fc	diff	diff file1 file2
Finds a string of text in a file	find	grep	grep this word or phrase thisfile.txt
Formats a diskette	format a: (if diskette is in A:)	mke2fs (or mformat[b])	/sbin/mke2fs /dev/fd0 (/dev/fd0 is the Linux equivalent of A:)
Displays command help	command /?	man[c]	man command
Creates a directory	mkdir	mkdir	mkdir directory
View a file	more	less[d]	less thisfile.txt
Renames a file	ren	mv	mv thisfile.txt thatfile.txt[e]
Displays your location in the file system	chdir	pwd	pwd
Changes directories with a specified path (absolute path)	cd pathname	cd pathname	cd /directory/directory
Changes directories with a relative path	cd ..	cd ..	cd ..
Displays the time	time	date	date
Shows amount of RAM and use	mem	free	free
Notes: a. Pico is a simple text editor; other editors you can use in place of Pico include Emacs and vi. b. This formats a disk for the DOS filesystem. c. You can also use info for some commands. d. The more pager can also be used to page through a file a screen at a time. e. The mv command can both move a file and, if you want to rename a file in the same directory, you "move" that file to the same directory with a new name, as in this example.

Python Проверка существования файла

Данный Python код проверяет существование файла и возможность работы с ним.

from os import path, access, R_OK  # W_OK for write permission.

PATH='./file.txt'

if path.exists(PATH) and path.isfile(PATH) and access(PATH, R_OK):
    print "File exists and is readable"
else:
    print "Either file is missing or is not readable"