Reading Input from the Keyboard

Python’s built-in input
function is used to read input from the keyboard. The input function reads a
piece of data that has been entered at the keyboard and returns that piece of
data, as a string, back to the program.

General
format:

variable =
input(prompt)

In the general format, prompt
is a string that is displayed on the screen.

Example:

name = input('What is
your name? ')

When the above
statement executes, the following things happen:

• The string 'What is
your name? ' is displayed on the screen.

• The program pauses
and waits for the user to type something on the keyboard and then to press the
Enter key.

• When the Enter key is
pressed, the data that was typed is returned as a string and assigned to the
name variable.

Reading
numeric data using input function

The input function
always returns the user’s input as a string, even if the user enters numeric
data. This can be a problem if you want to use the value in a math operation.
Math operations can be performed only on numeric values, not strings.

Python has built-in
functions that you can use to convert a string to a numeric type.

Example:

string_value =
input('How many hours did you work? ')

hours =
int(string_value)

OR

hours = int(input('How
many hours did you work? '))

The int( ) and float( )
functions work only if the item that is being converted contains a valid
numeric value. If the argument cannot be converted to the specified data type,
an error known as an exception occurs.