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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>
<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 <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> 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 class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The file is saved as part of saving the model in the database, so the actual
file name used on disk cannot be relied on until after the model has been
saved.</p>
</div>
</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 <a class="reference internal" href="../ref/files/file.html#django.core.files.File" title="django.core.files.File"><tt class="xref py py-class docutils literal"><span class="pre">django.core.files.File</span></tt></a> instance 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 documented attributes and methods
of the <a class="reference internal" href="../ref/files/file.html#django.core.files.File" title="django.core.files.File"><tt class="xref py py-class docutils literal"><span class="pre">File</span></tt></a> class.</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 class="row-odd"><th class="head">Argument</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><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 <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> setting.</td>
</tr>
<tr class="row-odd"><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 <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> 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 <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> 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
<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>.</p>
</div>
</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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