Delete a list element by value in Python
David Y.
—The Problem
In Python, how can I delete a list item by its value rather than its position?
The Solution
Python’s list.remove method provides this functionality. Given a value, it will search for that value in the list and delete the first instance it finds. If the supplied value is not found in the list, it raises a ValueException error. For example:
mylist = ['a', 'b', 'c', 'c', 'd'] mylist.remove('c') # will remove the first 'c' print(mylist) # will print ['a', 'b', 'c', 'd'] mylist.remove('c') # will remove the remaining 'c' print(mylist) # will print ['a', 'b', 'd'] try: mylist.remove('e') # will throw an exception except ValueError: print('Element to delete not found in list')
If you would like to remove all elements with a given value from a list, not just the first one, you can do this efficiently by rebuilding the list without those elements in a list comprehension:
mylist = ['a', 'b', 'c', 'c', 'd'] mylist = [item for item in mylist if item != 'c'] # rebuild the list without 'c's print(mylist) # will print ['a', 'b', 'd']
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