Deleting with `del`

Life with Python #5

Yes, more AI “art”. Dare I say, I am starting to get more specific and creative?

So today I learned about del in python. It is a keyword that has the simplest of functionalities, namely that it will delete objects. Deletable objects could be a variable, list item, dictionary entry, or even an entire list or dictionary.

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The basic syntax for using del is:

del <whatever_is_to_be_deleted>, <whatever_else_is_to_be_deleted>, ...

Now let’s take a closer look at the different contexts for using del, shall we?

• Deleting Variables/Objects
  When you use del on a variable/object, it removes the reference to that in memory. Basically, it will no longer be accessible in any way in the program, as if it never existed in the first place.

x = "whatever you want"
del x
print(x)  # Raises a NameError because x no longer exists

set_1 = {1,2,3}
del set_1
set_1.add(4) # we get a NameError

We can also have multiple variables/objects deleted in the same line by separating them with a comma. For example:

b = 'bee'
a = 10
z = {1:34,3:14}
del a, b, z
print(a) # NameError is raised as a no longer exists
print(b) # NameError again
print(z) # NameError again

Entire objects can be deleted such as sets, dictionaries, lists, any user-defined class objects etc.

• Deleting List Items and List Slices
  You can delete specific items from a list by specifying the index. You can also delete slices from lists as well. Consider the following example:

numbers = [1, 2, 3, 4, 5]
del numbers[2]
print(numbers)  # Output: [1, 2, 4, 5]
del numbers[1:3]
print(numbers)  # Output: [1, 5]

• Deleting Dictionary Entries
  To delete a key-value pair in a dictionary, you can use del with the key as shown below.

person = {"name": "Alice", "age": 25}
del person["age"] # CANNOT use del person.get("age")
print(person)  # Output: {"name": "Alice"}

That’s it from me for this time. del and out! :D Until next time!