I want to extract opcodes 'Assembly instructions' from malware binaries . and because I have large number of samples I don't want to do it invidiously .. instead I want to automate the process of doing that .. any suggestion ? I have done lots of research and I can see that I can use the IDA pro 'the GUI' for this but I am not sure if I can automate especially using the free version of IDA.Is there a python based tool which can do that and I don't mind to write a python script then to automate it. It may be important also to mention that I am working on linux not windows. 
Extracting Opcodes of a binary
malware;disassemblers
Yes, you can automate this by running IDA Pro with the -B command line switch:-B     batch mode. IDA will generate .IDB and .ASM files automatically