how to delete all variables in python code example

Example: del all variables python

def a_func():
    return 0
a_num = 5
print(dir())
>>> ['__builtins__', '__doc__', ..., 'a_func', 'a_num']
for element in dir():
    if element[0:2] != "__":
        del globals()[element]

del element
print(dir())
>>> ['__builtins__', '__doc__', ...]