CODEWITHSUNDEEP
pythonpython-3.x
Armend Veseli
Armend Veseli

Reputation: 143

Why does Python tell me "input(' ') ValueError: could not convert string to float" when converting user input?

print('Input a list of numbers to do statistics on them. Type stop to end the list.')

while True:
    number_list = []
    stop_input = False

    while stop_input == False:
        user_input = input('-> ')

        if float(user_input):
            number_list.append(user_input)                    

        elif user_input == 'stop':
            stop_input = True

    print('Sum:', sum(number_list))

The error is as follows:

if float(user_input):

ValueError: could not convert string to float: 'stop' (line 10).

I am typing input in as

1.0

2.0

3.0

stop

Upvotes: 0

Views: 526

Answers (1)

fferri
fferri

Reputation: 18940

float('stop') will raise an exception that you have to catch with a try: ... except ...: ... block.

Additionally, float(user_input) evaluates to False when user_input is 0.0 (or 0), so that number would never be added to the list.

You can change:

if float(user_input):
    number_list.append(user_input)

elif user_input == 'stop':
    stop_input = True

to:

try:
    number_list.append(float(user_input))
except ValueError:
    if user_input == 'stop':
        stop_input = True

to fix your program.

Upvotes: 2

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