从命令行运行Python脚本时，MySQLdb模块可以工作，但不能作为cron作业

Question

I am trying to create a cron job to run a python script I wrote, but for some reason the script only runs when I'm running it from the command line. It worked before, but I accidentally deleted my crontab. When the crontab I just wrote tries to run it, I get an error about the MySQLdb module being the wrong architecture:

    Traceback (most recent call last):
  File "/Users/myuser/Documents/EE_SFDC Integration/csv_reader/Weekly_Updates/Weekly_Confirmation/weekly_confirm.py", line 7, in <module>
    import MySQLdb
  File "/Library/Python/2.7/site-packages/MySQLdb/__init__.py", line 19, in <module>
    import _mysql
ImportError: dlopen(/Library/Python/2.7/site-packages/_mysql.so, 2): no suitable image found.  Did find:
    /Library/Python/2.7/site-packages/_mysql.so: mach-o, but wrong architecture

In my crontab, I've tried using the full path to several python versions (2.7 and 3.4), but I still get the issue. When I use 3.4, I don't get an error about MySQLdb, but I do get an error on a print .forma() statement being the wrong syntax.

But again, that doesn't happen when I run the script from the command line, so I expect this is not the correct version either.

The cron job looks like this:

14 12 * * * today=`date +"\%Y-\%m-\%d"` && /System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2 /Users/myuser/Documents/EE_SFDC\ Integration/csv_reader/Weekly_Updates/Weekly_Confirmation/weekly_confirm.py > /Users/myuser/Documents/EE/run_logs/weekly_sync_runlog_$today.txt 2>&1

Any help is much appreciated!

Answer 1

The error message typically means that you have a mismatch between the MySQLdb (or a dependency) and Python architecture.

That is, one of them are most likely 64-bit, while the other is 32-bit.

What happens if you try the following in a terminal?

$ /System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2
(Take note of the exact version)
>>> import platform
>>> print platform.architecture()
>>> import MySQLdb

Do it again, but this time with python from your path and see if they differ

$ python
>>> import platform
>>> print platform.architecture()
>>> import MySQLdb

Edit:

You might also check with file, what architecture the module is built for.

$ file /Library/Python/2.7/site-packages/_mysql.so
/Library/Python/2.7/site-packages/_mysql.so: Mach-O universal binary with 2 architectures
/Library/Python/2.7/site-packages/_mysql.so (for architecture x86_64):  Mach-O 64-bit bundle x86_64
/Library/Python/2.7/site-packages/_mysql.so (for architecture i386):    Mach-O bundle i386