␡
- 2.1 Program Output, the print Statement, and Hello World!
- 2.2 Program Input and the raw_input()Built-in Function
- 2.3 Comments
- 2.4 Operators
- 2.5 Variables and Assignment
- 2.6 Numbers
- 2.7 Strings
- 2.8 Lists and Tuples
- 2.9 Dictionaries
- 2.10 Code Blocks Use Indentation
- 2.11 if Statement
- 2.12 while Loop
- 2.13 for Loop and the range() Built-in Function
- 2.14 List Comprehensions
- 2.15 Files and the open() and file() Built-in Functions
- 2.16 Errors and Exceptions
- 2.17 Functions
- 2.18 Classes
- 2.19 Modules
- 2.20 Useful Functions
- 2.21 Exercises
This chapter is from the book
This chapter is from the book
This chapter is from the book
This chapter is from the book
2.2 Program Input and the raw_input()Built-in Function
The easiest way to obtain user input from the command line is with the raw_input() built-in function. It reads from standard input and assigns the string value to the variable you designate. You can use the int() built-in function to convert any numeric input string to an integer representation.
>>> user = raw_input('Enter login name: ')
Enter login name: root
>>> print 'Your login is:', user
Your login is: root
The earlier example was strictly for text input. A numeric string input (with conversion to a real integer) example follows below:
>>> num = raw_input('Now enter a number: ')
Now enter a number: 1024
>>> print 'Doubling your number: %d' % (int(num) * 2)
Doubling your number: 2048
The int() function converts the string num to an integer so that the mathematical operation can be performed. See Section 6.5.3 for more information in the raw_input() built-in function.