def _get_new_steplist(reqs_to_keep, old_step_data, req_ids):
	"""Returns a list similar to `old_step_data` but with unwanted requests removed.

	Uses the requests and request components in `old_step_data` and the entitiy ids in `req_ids` to determine which elements in `old_step_data` to keep.
	
	Parameters
	----------
	reqs_to_keep : dict
		Dictionary of requests and request components to keep
	old_step_data : list
		List of all the step data in the results file
	req_ids : dict
		Dictionary of entity ids for the entire results file
	
	Returns
	-------
	list
		List of just the step data to keep
	
	"""
	# Start a new list with just the time element from `old_step_data`  
	new_step_data = [old_step_data[1]]

	# Loop through the desired requests and components to pull elements
	# from `old_step_data` into `new_step_data`	
	for request in reqs_to_keep:
		# For each desired request 
		for req_comp in reqs_to_keep[request]:
			# For each desired request component, add that components
			# step data to `new_step_data`
			req_id = int(req_ids[request][req_comp])
			new_step_data.append(old_step_data[req_id])
	
	return new_step_data