error: command 'gcc' failed with exit status 1 while installing eventlet

I wanted to install eventlet on my system in order to have "Herd" for software deployment.. but the terminal is showing a gcc error:

  root@agrover-OptiPlex-780:~# easy_install -U eventlet
  Searching for eventlet
  Reading http://pypi.python.org/simple/eventlet/
  Reading http://wiki.secondlife.com/wiki/Eventlet
  Reading http://eventlet.net
   Best match: eventlet 0.9.16
    Processing eventlet-0.9.16-py2.7.egg
    eventlet 0.9.16 is already the active version in easy-install.pth

   Using /usr/local/lib/python2.7/dist-packages/eventlet-0.9.16-py2.7.egg
 Processing dependencies for eventlet
 Searching for greenlet>=0.3
Reading http://pypi.python.org/simple/greenlet/
Reading https://github.com/python-greenlet/greenlet
Reading http://bitbucket.org/ambroff/greenlet
Best match: greenlet 0.3.4
Downloading http://pypi.python.org/packages/source/g/greenlet/greenlet-   0.3.4.zip#md5=530a69acebbb0d66eb5abd83523d8272
Processing greenlet-0.3.4.zip
Writing /tmp/easy_install-_aeHYm/greenlet-0.3.4/setup.cfg
Running greenlet-0.3.4/setup.py -q bdist_egg --dist-dir /tmp/easy_install-_aeHYm/greenlet-0.3.4/egg-dist-tmp-t9_gbW
In file included from greenlet.c:5:0:
greenlet.h:8:20: fatal error: Python.h: No such file or directory
compilation terminated.
error: Setup script exited with error: command 'gcc' failed with exit status 1`

Why can't Python.h be found?

Your install is failing because you don't have the python development headers installed.

First update the packages with sudo apt update.

You can do this through apt on ubuntu/debian with:

sudo apt-get install python-dev 

for python3 use:

sudo apt-get install python3-dev

For eventlet you might also need the libevent libraries installed so if you get an error talking about that you can install libevent with:

sudo apt-get install libevent-dev