This is my sample database:

In my script now, I am adding elements to the list with the following code:
import pandas
data = pandas.read_excel("Sample database copy.xlsx")
name = dict(zip(data["Abbreviation"],data["Name"]))
list1 = []
incoming_msg = input('Please type what you want to add: ')
incoming_msg = incoming_msg.split() # split the string by space
if len(incoming_msg) == 2: # if there are two elements in the list (number and name)
list1 += [name[incoming_msg[1]]] * int(incoming_msg[0])
else:
list1.append(name[incoming_msg[0]])
So now if type "2 JO" my list will have two new elements "John" and "John".
Now I want to do exactly the same but for eliminating objects of a list. I tried to replace the current operator "+=" for "-=" but surprisingly it is not working. Any ideas on how I could solve this?
PS. I need to do it all out of the same input. I cannot ask separately for key and quantity. I want to make a replication of the above code but for removing the objects.