when i manually execute python script it works fine (cat /var/log/nxlog/pktdesign-alerts.log1|./sec-parse.py) , but whe nxlog calls keep on seeing the error messages below and scripot does not execute, 

===> when nxlog config was whats listed below produced error "2015-11-23 20:52:41 ERROR subprocess '4843' returned a non-zero exit value of 127"

<Output alertout-pktdesign>
    Module      om_file
    File        "/var/log/nxlog/pktdesign-alerts.log1"
    Exec        exec_async("/bin/sh", "-c", 'echo "' + $raw_event +  '"|./sec-parse.py' );
</Output>

===> when nxlog config was what's listed below produced error  "2015-11-23 21:25:41 ERROR subprocess '8319' returned a non-zero exit value of 1"

<Output alertout-pktdesign>
    Module      om_file
    File        "/var/log/nxlog/pktdesign-alerts.log1"
    Exec        exec_async("/bin/sh", "-c", 'echo "' + $raw_event +  '"|/etc/nxlog/sec-parse.py' );
</Output>

any help is appreciated.

thanks