Python Regular Expressions - removing all characters passed a certain character

I have a few regular expressions, for example, that looks like this
98374D90
483D39
3843930D393

Right now I have the python code taking out all characters and keeping integers like so:

ws = 98374D90
 clean = re.sub("\D", "", ws)
 

Which leaves me with 9837490 but what I need it to do is once it reaches the character "D" it drops the D and everything after it so 98374D90 would result in 98374 how would I do this?

Thanks for the help.

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