title: How to install GNU MPFR library on pythonanywhere
body: <p>I'm trying to install <code>bigfloat</code> and I am getting this message that seems to indicate I need the <code>mpfr</code> library first. How do I do this?<br>
  The message:  </p>
  
  <blockquote>
    <p>running build_ext building 'mpfr' extension creating build/temp.linux-x86_64-2.7 x86_64-linux-gnu-gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.7 -c mpfr. c -o build/temp.linux-x86_64-2.7/mpfr.o mpfr.c:344:18: fatal error: mpfr.h: No such file or directory #include "mpfr.h" ^ compilation terminated. error: command 'x86_64-linux-gnu-gcc' failed with exit status 1 </p>
  </blockquote>
  
  <p>I'm pretty new to python and pythonanywhere, so I don't know how to install libraries.</p>
  
  <p>I tried to find how to install a library using google, and I tried to use:  </p>
  
  <pre><code>pip install --user mpfr 
  </code></pre>
  
  <p>but I get this error message: </p>
  
  <blockquote>
    <p>Collecting mpfr Could not find a version that satisfies the requirement mpfr (from versions: ) No matching distribution found for mpfr </p>
  </blockquote>