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<h1><a href="../index.html">Django v1.2 documentation</a></h1>
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<div class="section" id="s-managing-files">
<span id="managing-files"></span><h1>Managing files<a class="headerlink" href="#managing-files" title="Permalink to this headline">¶</a></h1>
<div class="versionadded">
<span class="title">New in Django 1.0:</span> <a class="reference internal" href="../releases/1.0.html"><em>Please, see the release notes</em></a></div>
<p>This document describes Django’s file access APIs.</p>
<p>By default, Django stores files locally, using the <a class="reference internal" href="../ref/settings.html#std:setting-MEDIA_ROOT"><tt class="xref std std-setting docutils literal"><span class="pre">MEDIA_ROOT</span></tt></a> and
<a class="reference internal" href="../ref/settings.html#std:setting-MEDIA_URL"><tt class="xref std std-setting docutils literal"><span class="pre">MEDIA_URL</span></tt></a> settings. The examples below assume that you’re using these
defaults.</p>
<p>However, Django provides ways to write custom <a class="reference internal" href="#file-storage">file storage systems</a> that
allow you to completely customize where and how Django stores files. The
second half of this document describes how these storage systems work.</p>
<div class="section" id="s-using-files-in-models">
<span id="using-files-in-models"></span><h2>Using files in models<a class="headerlink" href="#using-files-in-models" title="Permalink to this headline">¶</a></h2>
<p>When you use a <a class="reference internal" href="../ref/models/fields.html#django.db.models.FileField" title="django.db.models.FileField"><tt class="xref py py-class docutils literal"><span class="pre">FileField</span></tt></a> or
<a class="reference internal" href="../ref/models/fields.html#django.db.models.ImageField" title="django.db.models.ImageField"><tt class="xref py py-class docutils literal"><span class="pre">ImageField</span></tt></a>, Django provides a set of APIs you can use
to deal with that file.</p>
<p>Consider the following model, using an <tt class="docutils literal"><span class="pre">ImageField</span></tt> to store a photo:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="k">class</span> <span class="nc">Car</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
<span class="n">name</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">CharField</span><span class="p">(</span><span class="n">max_length</span><span class="o">=</span><span class="mi">255</span><span class="p">)</span>
<span class="n">price</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">DecimalField</span><span class="p">(</span><span class="n">max_digits</span><span class="o">=</span><span class="mi">5</span><span class="p">,</span> <span class="n">decimal_places</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
<span class="n">photo</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">ImageField</span><span class="p">(</span><span class="n">upload_to</span><span class="o">=</span><span class="s">'cars'</span><span class="p">)</span>
</pre></div>
</div>
<p>Any <tt class="docutils literal"><span class="pre">Car</span></tt> instance will have a <tt class="docutils literal"><span class="pre">photo</span></tt> attribute that you can use to get at
the details of the attached photo:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="n">car</span> <span class="o">=</span> <span class="n">Car</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s">"57 Chevy"</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">car</span><span class="o">.</span><span class="n">photo</span>
<span class="go"><ImageFieldFile: chevy.jpg></span>
<span class="gp">>>> </span><span class="n">car</span><span class="o">.</span><span class="n">photo</span><span class="o">.</span><span class="n">name</span>
<span class="go">u'cars/chevy.jpg'</span>
<span class="gp">>>> </span><span class="n">car</span><span class="o">.</span><span class="n">photo</span><span class="o">.</span><span class="n">path</span>
<span class="go">u'/media/cars/chevy.jpg'</span>
<span class="gp">>>> </span><span class="n">car</span><span class="o">.</span><span class="n">photo</span><span class="o">.</span><span class="n">url</span>
<span class="go">u'http://media.example.com/cars/chevy.jpg'</span>
</pre></div>
</div>
<p>This object -- <tt class="docutils literal"><span class="pre">car.photo</span></tt> in the example -- is a <tt class="docutils literal"><span class="pre">File</span></tt> object, which means
it has all the methods and attributes described below.</p>
</div>
<div class="section" id="s-the-file-object">
<span id="the-file-object"></span><h2>The <tt class="docutils literal"><span class="pre">File</span></tt> object<a class="headerlink" href="#the-file-object" title="Permalink to this headline">¶</a></h2>
<p>Internally, Django uses a <tt class="docutils literal"><span class="pre">django.core.files.File</span></tt> any time it needs to
represent a file. This object is a thin wrapper around Python's <a class="reference external" href="http://docs.python.org/library/stdtypes.html#bltin-file-objects">built-in file
object</a> with some Django-specific additions.</p>
<p>Most of the time you'll simply use a <tt class="docutils literal"><span class="pre">File</span></tt> that Django's given you (i.e. a
file attached to a model as above, or perhaps an uploaded file).</p>
<p>If you need to construct a <tt class="docutils literal"><span class="pre">File</span></tt> yourself, the easiest way is to create one
using a Python built-in <tt class="docutils literal"><span class="pre">file</span></tt> object:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.core.files</span> <span class="kn">import</span> <span class="n">File</span>
<span class="go"># Create a Python file object using open()</span>
<span class="gp">>>> </span><span class="n">f</span> <span class="o">=</span> <span class="nb">open</span><span class="p">(</span><span class="s">'/tmp/hello.world'</span><span class="p">,</span> <span class="s">'w'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">myfile</span> <span class="o">=</span> <span class="n">File</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
</pre></div>
</div>
<p>Now you can use any of the <tt class="docutils literal"><span class="pre">File</span></tt> attributes and methods documented in
<a class="reference internal" href="../ref/files/file.html"><em>The File object</em></a>.</p>
</div>
<div class="section" id="s-file-storage">
<span id="file-storage"></span><h2>File storage<a class="headerlink" href="#file-storage" title="Permalink to this headline">¶</a></h2>
<p>Behind the scenes, Django delegates decisions about how and where to store files
to a file storage system. This is the object that actually understands things
like file systems, opening and reading files, etc.</p>
<p>Django's default file storage is given by the <a class="reference internal" href="../ref/settings.html#std:setting-DEFAULT_FILE_STORAGE"><tt class="xref std std-setting docutils literal"><span class="pre">DEFAULT_FILE_STORAGE</span></tt></a>
setting; if you don't explicitly provide a storage system, this is the one that
will be used.</p>
<p>See below for details of the built-in default file storage system, and see
<a class="reference internal" href="../howto/custom-file-storage.html"><em>Writing a custom storage system</em></a> for information on writing your own file
storage system.</p>
<div class="section" id="s-storage-objects">
<span id="storage-objects"></span><h3>Storage objects<a class="headerlink" href="#storage-objects" title="Permalink to this headline">¶</a></h3>
<p>Though most of the time you'll want to use a <tt class="docutils literal"><span class="pre">File</span></tt> object (which delegates to
the proper storage for that file), you can use file storage systems directly.
You can create an instance of some custom file storage class, or -- often more
useful -- you can use the global default storage system:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.core.files.storage</span> <span class="kn">import</span> <span class="n">default_storage</span>
<span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.core.files.base</span> <span class="kn">import</span> <span class="n">ContentFile</span>
<span class="gp">>>> </span><span class="n">path</span> <span class="o">=</span> <span class="n">default_storage</span><span class="o">.</span><span class="n">save</span><span class="p">(</span><span class="s">'/path/to/file'</span><span class="p">,</span> <span class="n">ContentFile</span><span class="p">(</span><span class="s">'new content'</span><span class="p">))</span>
<span class="gp">>>> </span><span class="n">path</span>
<span class="go">u'/path/to/file'</span>
<span class="gp">>>> </span><span class="n">default_storage</span><span class="o">.</span><span class="n">size</span><span class="p">(</span><span class="n">path</span><span class="p">)</span>
<span class="go">11</span>
<span class="gp">>>> </span><span class="n">default_storage</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="n">path</span><span class="p">)</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>
<span class="go">'new content'</span>
<span class="gp">>>> </span><span class="n">default_storage</span><span class="o">.</span><span class="n">delete</span><span class="p">(</span><span class="n">path</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">default_storage</span><span class="o">.</span><span class="n">exists</span><span class="p">(</span><span class="n">path</span><span class="p">)</span>
<span class="go">False</span>
</pre></div>
</div>
<p>See <a class="reference internal" href="../ref/files/storage.html"><em>File storage API</em></a> for the file storage API.</p>
</div>
<div class="section" id="s-the-built-in-filesystem-storage-class">
<span id="the-built-in-filesystem-storage-class"></span><h3>The built-in filesystem storage class<a class="headerlink" href="#the-built-in-filesystem-storage-class" title="Permalink to this headline">¶</a></h3>
<p>Django ships with a built-in <tt class="docutils literal"><span class="pre">FileSystemStorage</span></tt> class (defined in
<tt class="docutils literal"><span class="pre">django.core.files.storage</span></tt>) which implements basic local filesystem file
storage. Its initializer takes two arguments:</p>
<table class="docutils">
<colgroup>
<col width="30%" />
<col width="70%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">Argument</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><tt class="docutils literal"><span class="pre">location</span></tt></td>
<td>Optional. Absolute path to the directory that will
hold the files. If omitted, it will be set to the
value of your <tt class="docutils literal"><span class="pre">MEDIA_ROOT</span></tt> setting.</td>
</tr>
<tr><td><tt class="docutils literal"><span class="pre">base_url</span></tt></td>
<td>Optional. URL that serves the files stored at this
location. If omitted, it will default to the value
of your <tt class="docutils literal"><span class="pre">MEDIA_URL</span></tt> setting.</td>
</tr>
</tbody>
</table>
<p>For example, the following code will store uploaded files under
<tt class="docutils literal"><span class="pre">/media/photos</span></tt> regardless of what your <tt class="docutils literal"><span class="pre">MEDIA_ROOT</span></tt> setting is:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">django.db</span> <span class="kn">import</span> <span class="n">models</span>
<span class="kn">from</span> <span class="nn">django.core.files.storage</span> <span class="kn">import</span> <span class="n">FileSystemStorage</span>
<span class="n">fs</span> <span class="o">=</span> <span class="n">FileSystemStorage</span><span class="p">(</span><span class="n">location</span><span class="o">=</span><span class="s">'/media/photos'</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">Car</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
<span class="o">...</span>
<span class="n">photo</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">ImageField</span><span class="p">(</span><span class="n">storage</span><span class="o">=</span><span class="n">fs</span><span class="p">)</span>
</pre></div>
</div>
<p><a class="reference internal" href="../howto/custom-file-storage.html"><em>Custom storage systems</em></a> work the same way: you
can pass them in as the <tt class="docutils literal"><span class="pre">storage</span></tt> argument to a <tt class="docutils literal"><span class="pre">FileField</span></tt>.</p>
</div>
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<h3><a href="../contents.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Managing files</a><ul>
<li><a class="reference internal" href="#using-files-in-models">Using files in models</a></li>
<li><a class="reference internal" href="#the-file-object">The <tt class="docutils literal"><span class="pre">File</span></tt> object</a></li>
<li><a class="reference internal" href="#file-storage">File storage</a><ul>
<li><a class="reference internal" href="#storage-objects">Storage objects</a></li>
<li><a class="reference internal" href="#the-built-in-filesystem-storage-class">The built-in filesystem storage class</a></li>
</ul>
</li>
</ul>
</li>
</ul>
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