<h4 dir="auto">Code Sample, a copy-pastable example if possible</h4>
<p dir="auto">I Haven't written any custom code.</p>
<h4 dir="auto">Problem description</h4>
<p dir="auto">I'm trying to install Pandas with pip install pandas, and I'am encountering the following error:</p>
<div class="highlight highlight-source-shell notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="nvidia@tegra-ubuntu:~/opt$ sudo -H pip install pandas
Collecting pandas
  Using cached https://files.pythonhosted.org/packages/08/01/803834bc8a4e708aedebb133095a88a4dad9f45bbaf5ad777d2bea543c7e/pandas-0.22.0.tar.gz
  Could not find a version that satisfies the requirement Cython (from versions: )
No matching distribution found for Cython"><pre class="notranslate">nvidia@tegra-ubuntu:<span class="pl-k">~</span>/opt$ sudo -H pip install pandas
Collecting pandas
  Using cached https://files.pythonhosted.org/packages/08/01/803834bc8a4e708aedebb133095a88a4dad9f45bbaf5ad777d2bea543c7e/pandas-0.22.0.tar.gz
  Could not find a version that satisfies the requirement Cython (from versions: )
No matching distribution found <span class="pl-k">for</span> Cython</pre></div>
<p dir="auto">At first I tried to install Cython, then installing pandas, but the same behavior is encountered, my platfrom is arm-64 and is currently my bottleneck to develop.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="$pip --version"><pre class="notranslate"><code class="notranslate">$pip --version
</code></pre></div>
<p dir="auto">Now that pip 19 is out, we can attempt to re-add pyproject.toml</p>
<hr>
<p dir="auto">The release of pip version 10 and the presence of a <code class="notranslate">pyproject.toml</code> in our latest released versions gives problems for installing pandas in the following cases:</p>
<p dir="auto"><strong>Problem with installing pandas for Python 3.4</strong></p>
<ul dir="auto">
<li>You get the error <em>"Double requirement given: numpy ..."</em></li>
<li>The reason for this error is that pandas 0.21-0.22 no longer supports Python 3.4, and thus no longer distributes binary wheels for Python 3.4. Therefore, pip tries to install pandas from source, and this is what now started to fail with Pip version 10.</li>
<li><strong>Solution</strong>:
<ul dir="auto">
<li>
<p dir="auto">Install an older version of pandas</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="pip install pandas&lt;0.21"><pre class="notranslate"><code class="notranslate">pip install pandas&lt;0.21
</code></pre></div>
</li>
<li>
<p dir="auto">Workaround for package maintainers to specify the pandas version in <code class="notranslate">install_requires</code>: <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="314359671" data-permission-text="Title is private" data-url="https://github.com/pandas-dev/pandas/issues/20697" data-hovercard-type="issue" data-hovercard-url="/pandas-dev/pandas/issues/20697/hovercard?comment_id=381372004&amp;comment_type=issue_comment" href="https://github.com/pandas-dev/pandas/issues/20697#issuecomment-381372004">#20697 (comment)</a></p>
</li>
</ul>
</li>
<li>The fact that those version are downloaded for Python 3.4 (instead of an older compatible version) was a bug in our setup.py, and this will be fixed in future versions of pandas: <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="314372081" data-permission-text="Title is private" data-url="https://github.com/pandas-dev/pandas/issues/20698" data-hovercard-type="pull_request" data-hovercard-url="/pandas-dev/pandas/pull/20698/hovercard" href="https://github.com/pandas-dev/pandas/pull/20698">#20698</a></li>
</ul>
<p dir="auto"><strong>Problem with installing pandas on "special" platforms (32bit, PyPy, ARM, ...) (building from source)</strong>:</p>
<ul dir="auto">
<li>You get the error <em>"No matching distribution found for Cython"</em></li>
<li>The reason for this error is that we do not provide wheels for such python versions or platforms. In such a case, <code class="notranslate">pip</code> will try to build pandas from source, but this started to fail with pip version 10. This is because their limited support for PEP518, and they require that all build dependencies of pandas are installed from wheels (<a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="314376984" data-permission-text="Title is private" data-url="https://github.com/pypa/pip/issues/5229" data-hovercard-type="issue" data-hovercard-url="/pypa/pip/issues/5229/hovercard" href="https://github.com/pypa/pip/issues/5229">pypa/pip#5229</a>), which are often also not available on those python versions / platforms.</li>
<li><strong>Solution</strong>
<ul dir="auto">
<li>Use an older version of pip</li>
<li>Use <code class="notranslate">pip install pandas --no-build-isolation</code></li>
</ul>
</li>
<li>See eg <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="313701198" data-permission-text="Title is private" data-url="https://github.com/pandas-dev/pandas/issues/20666" data-hovercard-type="issue" data-hovercard-url="/pandas-dev/pandas/issues/20666/hovercard" href="https://github.com/pandas-dev/pandas/issues/20666">#20666</a>, <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="316399092" data-permission-text="Title is private" data-url="https://github.com/pandas-dev/pandas/issues/20771" data-hovercard-type="issue" data-hovercard-url="/pandas-dev/pandas/issues/20771/hovercard" href="https://github.com/pandas-dev/pandas/issues/20771">#20771</a></li>
</ul>