Trying to setup Python application, odd error

[Yoshimaster96]

Although python3 cannot find the Cython module:

[inline] python3 setup.py
Could not import cx_Freeze. Building executable not possible.
Traceback (most recent call last):
File "setup.py", line 13, in <module>
from Cython.Build import cythonize
ImportError: No module named 'Cython'[/inline]

pip3 says it has been installed:
[inline]
pip3 install Cython
Requirement already satisfied (use --upgrade to upgrade): Cython in /usr/local/lib/python3.4/dist-packages
Cleaning up...[/inline]

What is going on? How do I fix this?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Some more relevant information:
Pip version:

[inline] pip3 -V
pip 1.5.4 from /usr/lib/python3/dist-packages (python 3.4)[/inline]

Python version:

[inline] python3 -V
Python 3.4.6[/inline]

Tried to install from within Python session:

[inline] python3
Python 3.4.6 (default, May 11 2017, 18:25:35)
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> import Cython
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named 'Cython'
>>> sys.executable
'/usr/local/bin/python3'
>>> exit()

python3 -m pip install module
/usr/local/bin/python3: No module named pip

python3 -m pip Cython
/usr/local/bin/python3: No module named pip

sudo apt-get install python3-pip
Reading package lists... Done
Building dependency tree
Reading state information... Done
python3-pip is already the newest version.
The following packages were automatically installed and are no longer required:
libgsoap4 libvncserver0
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 189 not upgraded.[/inline]

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I tried cutting and pasting the stuff in /usr/local/lib/python3.4/dist-packages to /usr/local/lib/python3.4, but I end up with weird errors, like this:

[inline] Traceback (most recent call last):
File "setup.py", line 13, in <module>
from Cython.Build import cythonize
File "/usr/local/lib/python3.4/Cython/Build/__init__.py", line 1, in <module>
from .Dependencies import cythonize
File "/usr/local/lib/python3.4/Cython/Build/Dependencies.py", line 51, in <module>
from ..Compiler.Main import Context, CompilationOptions, default_options
File "/usr/local/lib/python3.4/Cython/Compiler/Main.py", line 30, in <module>
from .Symtab import ModuleScope
File "/usr/local/lib/python3.4/Cython/Compiler/Symtab.py", line 18, in <module>
from . import PyrexTypes
File "/usr/local/lib/python3.4/Cython/Compiler/PyrexTypes.py", line 17, in <module>
from .Code import UtilityCode, LazyUtilityCode, TempitaUtilityCode
ImportError: /usr/local/lib/python3.4/Cython/Compiler/Code.cpython-34m.so: undefined symbol: PyFPE_jbuf[/inline]

I am on Linux Mint Cinnamon 64-bit.