When is del useful in python?

Question

I can\'t really think of any reason why python needs the del keyword (and most languages seem to not have a similar keyword). For instance, rather than deletin

Answer 1

I would like to elaborate on the accepted answer to highlight the nuance between setting a variable to None versus removing it with del:

Given the variable foo = 'bar', and the following function definition:

def test_var(var):
    if var:
        print('variable tested true')
    else:
        print('variable tested false')

Once initially declared, test_var(foo) yields variable tested true as expected.

Now try:

foo = None
test_var(foo)

which yields variable tested false.

Contrast this behavior with:

del foo
test_var(foo)

which now raises NameError: name 'foo' is not defined.