Your post appears to be very much a homework question.
Forum rules prohibit doing homework.
Even though it may not be homework there is no way to really know from this end.
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More information and detail is needed:
ETL being "Extract, Transform, Load" - correct?
Show/post what you have done or attempted thus far. Some example or script of what you have coded thus far.
What code (Python if I understand correctly), what steps, etc..
Then refer to that code to ask specific questions.