After assigning values to a few variables, we could use the dir() function to show their existence. In the following example, variables n, pv, and r are shown among other names. At the moment, just ignore the first five objects in the following code, which start and end with two underscores:
>>>pv=100 >>>r=0.1 >>>n=5 >>>dir() ['__builtins__', '__doc__', '__loader__', '__name__', '__package__', 'n', 'pv', 'r']
Sometimes, when we write our programs, it might be a good idea to delete those variables that we no longer need. In this case, we could use the del() function to remove or unsign a variable. In the following example, we assign a value to rate, show its value, delete it, and type the variable name trying to retrieve its value again:
>>>rate=0.075 >>>rate 0.075
The value 0.075 seen in the previous code is an output, because the variable called rate was assigned...