I am a newbie to Python and I was trying my hand at the following problem: I want to add numbers entered by the user. Here is my program
add = 0 num = input('Enter a number:') add = add + num while num != ' ' : num = input('Next number:') add = add + num print add I want to terminate the program when a blank is entered. So I know the problem is with line 4. What would be the correct syntax?
Thanks in advance for your help
In python 2.7 user input should be processed using raw_input
This is because input is semantically equivalent to:
eval(raw_input(prompt)) which, when given an empty string, will cause the following line of code:
eval('') will return an EOF error while parsing, since empty is not a valid object to parse.
Since raw_string doesnt parse the string into an int you'll also have to use int() to convert it when you do the addition.
You also need to change to while statement:
add = 0 num = raw_input('Enter a number:') # you cant do a + here what if the user hits enter right away. if num: add = int(num) while num: # enter will result in a null string not a space num = raw_input('Next number:') if num: add = add + int(num) print add Try following and read a bit.
>>> help(input) >>> help(raw_input) >>> s=raw_input() <return right here> >>> s '' >>> s=raw_input() <one space followed by return here> >>> s ' ' >>> 