python - ValueError: could not convert string to float -

so... have primitive calculator runs fine on cellphone, when try run on windows 10 get...

valueerror: not convert string float

i don't know problem is, i've tried using raw_input doesn't work ether. please keep in mind i'm green , not aware of methods getting around problem this

num1 = float(input ()) #take float , store chars = input () #take string          , store num2 = float(input ()) 

your code convert string integers in below statement

num1 = float(input ()) #take float , store ex 13 print num1 # output 13.0 

if provide 13 input give output 13.0 if provide someonee input give valueerror

and same case of raw_input() difference default raw_input() takes input string , input() takes input provided function