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36. Unicode and Byte Strings > String Basics
String Basics
Before we look at any code, let’s begin with a general overview of Python’s string model. To understand why 3.0 changed the way it did on this front, we have to start with a brief look at how characters are actually represented in computers.
Most programmers think of strings as series of characters used to represent textual data. The way characters are stored in a computer’s memory can vary, though, depending on what sort of character set must be recorded.
The ASCII standard was created in the
U.S., and it defines many U.S. programmers’ notion of text strings.
ASCII defines character codes from 0 through 127 and allows each
character to be stored in one 8-bit byte (only 7 bits of which are
actually used). For example, the ASCII standard maps the character
'a' to the integer value 97 (0x61 in hex), which is stored in a
single byte in memory and files. If you wish to see how this works,
Python’s ord built-in function
gives the binary value for a character, and chr returns the character for a given
integer code value:
