如何只输入字符串值“ stop”，“”，然后检查并转换为浮点数

Question

Hi I am having trouble with the end of my loop. I need to accept the input as a string to get the "stop" or the "" but I don't need any other string inputs. Inputs are converted to float and then added to a list but if the user types "bob" I get the conversion error, and I cant set the input(float) because then I can't accept "stop".

Full current code is below.

My current thinking is as follows:

1. check for "stop, ""
2. check if the input is a float.
3. if its not 1 or 2, then ask for a valid input.

Any ideas please? If its something simple just point me in the direction and i'll try churn it out. Otherwise...

Thanks

# Write a progam that accepts an unlimited number of input as integers or floating point.
# The input ends either with a blank line or the word "stop".


mylist = []

g = 0
total = 0
avg = 0


def calc():
    total = sum(mylist);
    avg = total / len(mylist);
    print("\n");
    print ("Original list input: " + str(mylist))
    print ("Ascending list: " + str(sorted(mylist)))
    print ("Number of items in list: " + str(len(mylist)))
    print ("Total: " + str(total))
    print ("Average: " + str(avg))


while g != "stop":
    g = input()
    g = g.strip()  # Strip extra spaces from input.
    g = g.lower()  # Change input to lowercase to handle string exceptions.
    if g == ("stop") or g == (""):
        print ("You typed stop or pressed enter") # note for testing
        calc() # call calculations function here
        break

# isolate any other inputs below here ????? ---------------------------------------------
        while g != float(input()):
            print ("not a valid input")
    mylist.append(float(g))

Answer 1

I think the pythonic way would be something like:

def calc(mylist): # note the argument
    total = sum(mylist)
    avg = total / len(mylist) # no need for semicolons
    print('\n', "Original list input:", mylist)
    print("Ascending list:", sorted(mylist))
    print ("Number of items in list:", len(mylist))
    print ("Total:", total)
    print ("Average:", avg)

mylist = []
while True:
   inp = input()
   try:
       mylist.append(float(inp))
   except ValueError:
       if inp in {'', 'stop'}:
            calc(mylist)
            print('Quitting.')
            break
       else:
            print('Invalid input.')