PyPDF2 won't extract all text from PDF
<p>I'm trying to extract text from a PDF (<a href="https://www.sec.gov/litigation/admin/2015/34-76574.pdf" rel="noreferrer">https://www.sec.gov/litigation/admin/2015/34-76574.pdf</a>) using PyPDF2, and the only result I'm getting is the following string:</p>

<pre><code>b''
</code></pre>

<p>Here is my code:</p>

<pre><code>import PyPDF2
import urllib.request
import io

url = 'https://www.sec.gov/litigation/admin/2015/34-76574.pdf'
remote_file = urllib.request.urlopen(url).read()
memory_file = io.BytesIO(remote_file)

read_pdf = PyPDF2.PdfFileReader(memory_file)
number_of_pages = read_pdf.getNumPages()
page = read_pdf.getPage(1)
page_content = page.extractText()
print(page_content.encode('utf-8'))
</code></pre>

<p>This code worked correctly on a few of the PDFs I'm working with (e.g. <a href="https://www.sec.gov/litigation/admin/2016/34-76837-proposed-amended-distribution-plan.pdf" rel="noreferrer">https://www.sec.gov/litigation/admin/2016/34-76837-proposed-amended-distribution-plan.pdf</a>), but the others like the file above didn't work. Any idea what's wrong?</p>