Loop that adds user inputted numbers and breaks when user types “end”

Question

Create a function that expects no arguments. The function asks user to enter a series of numbers greater than or equal to zero, one at a time. The user types end to indicate tha

Answer 1

Think about what your loop is checking for:

"Do this, while the number is greater than or equal to 0 and it is not 'end'`.

Which value satisfies both conditions? If I enter 'end' then does it satisfy both criteria; because your loop will only break if both conditions are true.

So you really want or not and.

Once you solve that issue, you'll run into another problem:

>>> def sum_function():
...     number = 0
...     while number >= 0 or number is not 'end':
...         number = number + float(input('Enter a number: '))
...     return number
... 
>>> sum_function()
Enter a number: 1
Enter a number: 3
Enter a number: end
Traceback (most recent call last):
  File "", line 1, in 
  File "", line 4, in sum_function
ValueError: could not convert string to float: end

The problem here is that you are converting everything to a float immediately after its entered; so as soon as someone enters 'end', your program crashes because it cannot convert 'end' to a float.

Try to solve that one yourself :-)