["python","python-3.x","python-2.7","input","int"]
How can I read inputs as numbers?

Why are x and y strings instead of ints in the below code? (Note: in Python 2.x use raw_input(). In Python 3.x use input(). raw_input() was renamed to input() in Python 3.x) play = True while play: x = input("Enter a number: ") y = input("Enter a number: ") print(x + y) print(x - y) print(x * y) print(x / y) print(x % y) if input("Play again? ") == "no": play = False
Since Python 3, input returns a string which you have to explicitly convert to int, like this x = int(input("Enter a number: ")) y = int(input("Enter a number: ")) You can accept numbers of any base like this >>> data = int(input("Enter a number: "), 8) Enter a number: 777 >>> data 511 >>> data = int(input("Enter a number: "), 16) Enter a number: FFFF >>> data 65535 >>> data = int(input("Enter a number: "), 2) Enter a number: 10101010101 >>> data 1365 The second parameter tells it the base of the number and then internally it understands and converts it. If the entered data is wrong it will throw a ValueError. >>> data = int(input("Enter a number: "), 2) Enter a number: 1234 Traceback (most recent call last): File "<input>", line 1, in <module> ValueError: invalid literal for int() with base 2: '1234' For values that can have a fractional component, the type would be float rather than int: x = float(input("Enter a number:")) Differences between Python 2 and 3 Summary Python 2's input function evaluated the received data, converting it to an integer implicitly (read the next section to understand the implication), but Python 3's input function does not do that anymore. Python 2's equivalent of Python 3's input is the raw_input function. Python 2.x There were two functions to get user input, called input and raw_input. The difference between them is, raw_input doesn't evaluate the data and returns as it is, in string form. But, input will evaluate whatever you entered and the result of evaluation will be returned. For example, >>> import sys >>> sys.version '2.7.6 (default, Mar 22 2014, 22:59:56) \n[GCC 4.8.2]' >>> data = input("Enter a number: ") Enter a number: 5 + 17 >>> data, type(data) (22, <type 'int'>) The data 5 + 17 is evaluated and the result is 22. When it evaluates the expression 5 + 17, it detects that you are adding two numbers and so the result will also be of the same int type. So, the type conversion is done for free, and 22 is returned as the result of the input and stored in the data variable. You can think of input as the raw_input composed with an eval call. >>> data = eval(raw_input("Enter a number: ")) Enter a number: 5 + 17 >>> data, type(data) (22, <type 'int'>) Note: You should be careful when you are using input in Python 2.x. I explained why one should be careful when using it, in this answer. But, raw_input doesn't evaluate the input and returns as it is, as a string. >>> import sys >>> sys.version '2.7.6 (default, Mar 22 2014, 22:59:56) \n[GCC 4.8.2]' >>> data = raw_input("Enter a number: ") Enter a number: 5 + 17 >>> data, type(data) ('5 + 17', <type 'str'>) Python 3.x Python 3.x's input and Python 2.x's raw_input are similar and raw_input is not available in Python 3.x. >>> import sys >>> sys.version '3.4.0 (default, Apr 11 2014, 13:05:11) \n[GCC 4.8.2]' >>> data = input("Enter a number: ") Enter a number: 5 + 17 >>> data, type(data) ('5 + 17', <class 'str'>)