python - Loop that adds user inputted numbers and breaks when user types "end" -

create function expects no arguments. function asks user enter series of numbers greater or equal zero, 1 @ time. user types end indicate there no more numbers. function computes sum of values entered.

i'm supposed able while loops , if statements.

the main issue i'm running don't know how make "end" stops loop, rather add value.

def sumfunction(): """sum of values entered"""  number = 0 while number >= 0 , number not "end":     number = number + (float(input("enter next number: "))) return number 

think loop checking for:

"do this, while number greater or equal 0 , not 'end'`.

which value satisfies both conditions? if enter 'end' satisfy both criteria; because loop break if both conditions true.

so want or not and.

once solve issue, you'll run problem:

>>> def sum_function(): ...     number = 0 ...     while number >= 0 or number not 'end': ...         number = number + float(input('enter number: ')) ...     return number ...  >>> sum_function() enter number: 1 enter number: 3 enter number: end traceback (most recent call last):   file "<stdin>", line 1, in <module>   file "<stdin>", line 4, in sum_function valueerror: not convert string float: end 

the problem here converting float after entered; enters 'end', program crashes because cannot convert 'end' float.

try solve 1 :-)