---
layout: default
navsection: sdk
navmenu: Python
title: "Python SDK"

...

The Python SDK provides a generic set of wrappers so you can make API calls easily. It performs some validation before connecting to the API server: for example, it refuses to do an API call if a required parameter is missing.

The library also includes some conveniences for use in Crunch scripts; see "Crunch utility libraries":crunch-utility-libraries.html for details.

h3. Installation

If you are logged in to an Arvados VM, the Python SDK should be installed.

To use the Python SDK elsewhere, you can either install the Python SDK via PyPI or build and install the package using the arvados source tree.

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The Python SDK requires Python 2.7
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h4. Option 1: install with PyPI

<notextile>
<pre>
$ <code class="userinput">sudo apt-get install python-pip python-dev libattr1-dev libfuse-dev pkg-config</code>
$ <code class="userinput">sudo pip install arvados-python-client</code>
</pre>
</notextile>

_If your version of @pip@ is 1.4 or newer, the @pip install@ command might give an error: "Could not find a version that satisfies the requirement arvados-python-client". If this happens, fix it by adding a @--pre@ flag:_

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<pre>
$ <code class="userinput">sudo pip install --pre arvados-python-client</code>
</pre>
</notextile>

h4. Option 2: build and install from source

<notextile>
<pre>
~$ <code class="userinput">sudo apt-get install python-dev libattr1-dev libfuse-dev pkg-config</code>
~$ <code class="userinput">git clone https://github.com/curoverse/arvados.git</code>
~$ <code class="userinput">cd arvados/sdk/python</code>
~/arvados/sdk/python$ <code class="userinput">./build.sh</code>
~/arvados/sdk/python$ <code class="userinput">sudo python setup.py install</code>
</pre>
</notextile>

h4. Test installation

If the SDK is installed and your @ARVADOS_API_HOST@ and @ARVADOS_API_TOKEN@ environment variables are set up correctly (see "api-tokens":{{site.baseurl}}/user/reference/api-tokens.html for details), @import arvados@ should produce no errors:

<notextile>
<pre>$ <code class="userinput">python</code>
Python 2.7.4 (default, Sep 26 2013, 03:20:26) 
[GCC 4.7.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> <code class="userinput">import arvados</code>
>>> <code class="userinput">arvados.api('v1')</code>
&lt;apiclient.discovery.Resource object at 0x233bb50&gt;
</pre>
</notextile>

h3. Examples

Get the User object for the current user:

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<pre><code class="userinput">current_user = arvados.api('v1').users().current().execute()
</code></pre>
</notextile>

Get the UUID of an object that was retrieved using the SDK:

<notextile>
<pre><code class="userinput">my_uuid = current_user['uuid']
</code></pre>
</notextile>

Retrieve an object by ID:

<notextile>
<pre><code class="userinput">some_user = arvados.api('v1').users().get(uuid=my_uuid).execute()
</code></pre>
</notextile>

Create an object:

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<pre><code class="userinput">test_link = arvados.api('v1').links().create(
    body={'link_class':'test','name':'test'}).execute()
</code></pre>
</notextile>

Update an object:

<notextile>
<pre><code class="userinput">arvados.api('v1').links().update(
    uuid=test_link['uuid'],
    body={'properties':{'foo':'bar'}}).execute()
</code></pre>
</notextile>

Get a list of objects:

<notextile>
<pre><code class="userinput">repos = arvados.api('v1').repositories().list().execute()
len(repos['items'])</code>
2
<code class="userinput">repos['items'][0]['uuid']</code>
u'qr1hi-s0uqq-kg8cawglrf74bmw'
</code></pre>
</notextile>

h3. Notes

The general form of an API call is:

<notextile>
<pre><code class="userinput">arvados.api(<i>api_version</i>).<i>plural_resource_type</i>().<i>api_method</i>(<i>parameter</i>=<i>value</i>, ...).execute()
</code></pre>
</notextile>

Many API methods accept a parameter whose name is the same as the resource type. For example, @links.create@ accepts a parameter called @link@. This parameter should be given as @body@.

<notextile>
<pre><code class="userinput">arvados.api('v1').links().create(
    uuid=test_link['uuid'],
    body={'properties':{'foo':'bar'}}).execute()
</code></pre>
</notextile>

One way to make API calls slightly less verbose is:

<notextile>
<pre><code class="userinput">arv = arvados.api('v1')
j = arv.jobs().list().execute()
</code></pre>
</notextile>

The SDK retrieves the list of API methods from the server at run time. Therefore, the set of available methods is determined by the server version rather than the SDK version.