Can't find Python.h when compiling PyCaffe on Ubuntu 14.04 - python-3.x

Question

I'm trying to install PyCaffe for Python 3.5.3 on AWS EC2 with Ubuntu 14.04 without Anaconda, following the installation instructions.
I successfully compiled it on the same machine for Python 2.7 but when compiling for version 3.5 I get the following error:
ubuntu#ip-172-31-3-227:~/caffe$ make pycaffe
CXX/LD -o python/caffe/_caffe.so python/caffe/_caffe.cpp
python/caffe/_caffe.cpp:1:52: fatal error: Python.h: No such file or directory
#include <Python.h> // NOLINT(build/include_alpha)
I saw this post and performed:
sudo apt-get install python3-dev
I found this, so I performed the equivalent command for Python 3.5:
for req in $(cat requirements.txt); do sudo pip3.5 install $req; done
All installations worked but it didn't fix the problem.
I many other posts on similar problems but not this exact problem (so if you find something please check that it's really the same situation before rushing to say I didn't look well enough).
P.S.
I also saw this post but I don't understand which directories to add to the path.

Answer 1

When you do a pip install package,when pip finds new version,it uninstall the current one(dateutil in your case) when the package was installed using certain permission,pip needs the same permission to uninstall/upgrade it.
A quick fix would be to change this
`for req in $(cat requirements.txt); do pip3.5 install $req; done` to
for req in $(cat requirements.txt); do sudo pip3.5 install $req; done
It seems you dont have permission to access /usr/local/lib/python3.5/ folder as user,the packages that goes in /usr/local are required by the system but only available to you and only you on the system, i assume since only only they are restricted to you and pip want to access assuming that no restriction is there,then it get permission denied ,so you might consider doing
for req in $(cat requirements.txt); do pip3.5 --user yourusername install $req; done
the alternative is to remove any restriction to execute and write on that folder
by doing chmod -R 777 /usr/local/lib/python3.5/ which is usually not recommended but the problem you need pip to be able to read,write,execute anything in that folder.