Python module "cx_Oracle" module could not be found
Solution 1
Yes, you have to have an Oracle client installed at your side.
From the cx_ORacle README
"Please note that an Oracle client (or server) installation is required in order to use cx_Oracle. If you do not require the tools that come with a full client installation, it is recommended to install the Instant Client which is far easier to install."
EDIT link to Instant Client: http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html
Solution 2
# - This import requires appropriate oraocciXX.dll to be available in PATH (on windows)
# (Probably LD_LIBRARY_PATH or LD_LIBRARY_PATH64 on POSIX)
# where XX is the oracle DB version, e.g. oraocci11.dll for Oracle 11g.
# - This dll is part of the Oracle Instant client pkg available here:
# http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html
# - Also ensure that python, cx_Oracle and Oracle Client are of same arch (32 or 64-bit)
#
import cx_Oracle
You can find out arch (32 or 64-bit) for:
- python by just running the python in interactive mode on command line.
- cx_Oracle: look at the name of downloaded file.
- Oracle Client:
- run the sqlplus that's part of your client package
- start Task Manager and see if sqlplus.exe has "*32" next to it (=32 bit) or not (=64 bit)
- if you don't have sqlplus, use
dumpbin /headers oraocciXX.dll
- If you're using POSIX you probably would already know. Use
file oraocciXX.so
Finally if you still don't understand here is really for dummies instructions:
- Ensure you've installed 32-bit versions of python, cx_Oracle and Oracle Instant Client. These could also be 64-bit, but must be same for all 3. Can not mix and match. Links:
-
Oracle Instant Client Lets say it's installed in
C:\ProgFiles\OraClient\11_2
- cx_Oracle
- Python
-
Oracle Instant Client Lets say it's installed in
- Windows:
set PATH=%PATH%;C:\ProgFiles\OraClient\11_2
- POSIX (Linux/Unix/Solaris...) <-- Untested..
export LD_LIBRARY_PATH=/path/to/your/32bit/oraocciXX.so
- (64 bit)
export LD_LIBRARY_PATH64=/path/to/your/64bit/oraocciXX.so
- run
path-to-python/python.exe -c "import cx_Oracle"
to test whether your setup is working or not.- if it prints
- nothing: then it's successful.
-
ImportError: DLL load failed: The specified module could not be found
: then oraocciXX is not found. Setup the env vars correctly. -
ImportError: DLL load failed: %1 is not a valid Win32 application
: You have a 32/64 bit mismatch.
Solution 3
After having been trying to solve this issue for days, I found out that set PATH=%PATH%:<insert Oracle home here>
did not do the trick for me. I had to go into my Windows XP system properties and append the Oracle home to the 'path' variable under 'System variables'.
Chen Xie
Updated on August 11, 2020Comments
-
Chen Xie over 3 years
I recently installed cx_Oracle module on my machine, in order to connect to a remote Oracle database server. (I have no Oracle client at my side).
- Python: Version 2.7 x86
- Oracle: Verision 11.1.X x64
- Cx_Oracle:Verion-5.1.2-11g.win32-py2.7
Then everytime I run my script, it fails and print the following message:
ImportError: DLL load failed: The specified module could not be found.
I found a related post at Here, so I am wondering if I anyway have to have an Oracle client at my side where the python script is invoked.
Can anyone help me out? Thanks in advance.
-
Chen Xie over 11 yearsThanks for the reply, which is really helpful. Another question stands out after that as I moved my script into another environment where an X64 version Oracle is installed, the script failed. I did some research and found that might be due to the fact that the oracle client is 64bit and the python version is 32bit.
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Chen Xie over 11 yearsThe aforementioned issue solved, by having a "dummy" 32bit Oracle client, and set up the environment variable "ORACLE_HOME" properly to the dummy client path.
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John Gaines Jr. over 11 yearsYes, the oracle client and the Python must match in bits for them to work together.
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user584583 almost 10 yearsalso helpful stackoverflow.com/questions/20159566/…
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DocZerø almost 8 yearsTo check whether a binary file (dll or exe) is 32-bit or 64-bit, you could also use
sigcheck
by SysInternals. More info at http://superuser.com/a/808127/283407