Asking the User For Input

Sometimes we would like to take the value for a variable from the user via their keyboard. Python provides a built-in function called raw_input() that gest input from the keyboard. When this function is called the program is stopped from executing and waits for the user to give an input. The execution of the program continues soon as the user presses Enter or Return key on keyboard. After pressing Enter or Return key the raw_input() function returns what the user typed as a string.

>>>input = raw_input(“Enter your name: “) 
James 
>>>print input 
James 
>>>type (input) 

Before getting input from a user, it is a good idea to print a prompt telling the user what to input. You can pass a string to raw_input to be displayed to the user before pausing for input:

>>>name = raw_input(“Enter your name: \n”)
Enter your name: 
James 
>>>print name 
James

The sequence \n at the end of the prompt represents a newline which is a special character that causes a line break. That’s why the user’s input appears below the prompt.

The raw_input function returns string but if you expect the user to write an integer than you need to convert the string into integer using int(). For example

>>>speed = (“Enter the maximum speed of your car(km/h): \n “)
Enter the maximum speed of your car(km/h): 
220.0
>>>distance=(“Enter a desired distance (km) : \n”)
Enter a desired distance(km):
5.0
>>>type(speed)

>>>type(distance)

>>>v = int(speed)
>>>type(speed)

>>>s= int(distance)
>>>type(distance)

>>> t = s/v
0.0227272727273

If you don’t include transformation to integer for this program the Python will return ValueError.