Python + cx_Oracle: unable to get Oracle environment processing

Background .
My OS is Win7 64bit.
My Python is 2.7 64 bit from python-2.7.8.amd64.msi
My cx_Oracle 5.0 64 bit is from cx_Oracle-5.0.4-10g-unicode.win-amd64-py2.7.msi
My Oracle client is 10.1 (I don't know the 32 or 64 arch, but SQL * Plus is 10.1.0.2.0

The database is Oracle Database 10g Enterprise Edition version 10.2.0.4.0 - 64bit
PL / SQL Release 10.2.0.4.0 -
CORE production 10.2.0.4.0
TNS production for Windows 64 bit: version 10.2.0.4.0 -
NLSRTL Production Version 10.2.0.4.0 - Production

ORACLE_HOME , added from haki's answer.
C: \ Oracle \ product \ 10.1.0 \ Client_1 \

The job problem does not persist.

ORACLE_HOME Try Oracle instantly from instantclient-basic-win64-10.2.0.5.zip C: \ instantclient_10_2 \

C: \ Users \ PavilionG4> sqlplus Lee / 123 @chstchmp
SQL * Plus Initialization Error 6
Message file sp1.msb not found
SP2-0750: You may need to set ORACLE_HOME to Oracle software directory

My sql * plus won't let me install Oracle.

ORACLE_HOME Go back to site C: \ Oracle \ product \ 10.1.0 \ Client_1 \

PATH variable
C: \ Program Files (x86) \ Seagate Software \ NOTES \
C: \ Program Files (x86) \ Seagate Software \ NOTES \ DATA \
C: \ Program Files (x86) \ Java \ jdk1.7.0 _05 \ bin
C : \ Oracle \ product \ 10.1.0 \ Client_1 \ Bin
C: \ Oracle \ product \ 10.1.0 \ Client_1 \ JRE \ 1.4.2 \ Bin \ client
C: \ Oracle \ product \ 10.1.0 \ Client_1 \ JRE \ 1.4.2 \ bin
C: \ application \ PavilionG4 \ product \ 11.2.0 \ dbhome_1 \ Bin
C: \ application \ PavilionG4 \ product \ 11,2.0 \ client_2 \ bin
c: \ Program Files (x86) \ AMD APP \ bin \ x86_64
c: \ Program Files (x86) \ AMD APP \ bin \ x86
C: \ Windows \ system32
C: \ Windows
C: \ Windows \ System32 \ Wbem
C: \ Windows \ System32 \ WindowsPowerShell \ v1.0 \
c: \ Program Files (x86) \ ATI Technologies \ ATI.ACE \ Core-Static
C: \ Users \ PavilionG4 \ AppData \ Local \ Smartbar \ Application \
C: \ PROGRA ~ 2 \ IBM \ SQLLIB \ BIN
C: \ PROGRA ~ 2 \ IBM \ SQLLIB \ FUNCTION
C: \ Program Files \ gedit \ bin
C: \ Kivy-1.7.2-w32
C: \ Program Files (x86) \ ZBar \ binj
C: \ Program Files (x86) \ Java \ jdk1.7.0_05 \ bin
C: \ Program Files \ MATLAB \ R2013a \ runtime \ win64
C: \ Program Files \ MATLAB \ R2013a \ b to
C: \ python27

TNS :
C: \ Oracle \ product \ 10.1.0 \ Client_1 \ NETWORK \ ADMIN \ tnsnames.ora
REPORT1 =
(DESCRIPTION =
  (ADDRESS_LIST =
    (ADDRESS = (PROTOCOL = TCP) (HOST = 172.28.128.110) (PORT = 1521) )
  )
  (CONNECT_DATA =
    (SERVICE_NAME = REPORT1)
  )
)

f1.py shows me an error
import cx_Oracle
ip = '172,25,25,42'
port = 1521
SID = 'REPORT1'
dns_tns = cx_Oracle.makedsn (ip, port, SID)
connection = cx_Oracle.connect (u "Li", u "123", dns_tns)
cursor = connection.cursor () connection.close ()

Traceback error (last call last):
File "f1.py", line 6, in
  connection = cx_Oracle.connect (u "Lee", u "123", dns_tns)
cx_Oracle.InterfaceError: Unable to get Oracle environment handle

Questions
1. How to get the processing of the Oracle environment?
I searched for sites. Unfortunately they don't address my problem at all.
2. How do I let Python use another Oracle client without affecting the existing one?