I am looking for a way to delete elements from abaqus inp. The analysis type is dynamic explicit and elements are S4R. 
I should notice that elements which should be deleted are updated in a matlab optimization cycle.
Is there any way except using subroutine VUMAT?(even python scripting is preferred)
any idea will appreciated.
Thank you for reply. I tried your advice, I deleted the elements that I wanted to be removed from *.inp file. But when I imported the the *.inp, ABAQUS did not accept the file and gave error.
What I understood from your answer is that If I could not change *.inp file manually, It would not be possible to make change by python. 
Excuse me if I did not explain clearly. I think It is better to ask my question in this way:
I have an inp file containing a crash box simulation and dynamic explicit analysis applied on it.
I want this tube have some void elements before analysis. So I should manipulate the *.inp file. (This FE model will be used for topology optimization purpose in matlab)
changing inp by deleting element