#wget https://www.python.org/ftp/python/3.5.1/Python-3.5.1.tar.xz
#xz -d Python-3.5.1.tar.xz
#tar xvf Python-3.5.1.tar
#cd Python-3.5.1
#./configure --prefix=/usr
#make
#make altinstall

-----------------------------------

so far so good

but afterwards

$python3.5
>>>import base64

results in

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.5/base64.py", line 10, in <module>
    import struct
  File "/usr/lib/python3.5/struct.py", line 13, in <module>
    from _struct import *
ImportError: No module named '_struct'

------------------------------------------

>>>import sys
>>>sys.path
['', '/usr/lib/python35.zip', '/usr/lib/python3.5', '/usr/lib/python3.5/plat-linux', '/usr/lib/lib-dynload', '/usr/lib/python3.5/site-packages']

------------------------------------------

this path is wrong '/usr/lib/lib-dynload'
correctly it should point to the '/usr/lib64/python3.5/lib-dynload' as per the destination folders generated and used via configure / make / make altinstall

thank you
yaro-yaro