Operations for Text Processing

Abstract

Information is printed/displayed in natural language character combinations. But computer communication and storage systems use only bit streams. Unicode which defines universally accepted conversion between character and bit streams is the basis to bridge the gap between the two. Different coding schemes of conversion are in vogue—UTF8 being the most widely used one. UTF8 is explained and coding/decoding related constructs in Python dealt with in detail. Character streams as strings and binary string related operations are treated comprehensively. ‘Bytes’ and ‘bytearray’ as sequence representations and number representations in different forms (binary, octal, hex, decimal, and radix-specified) and their conversions come in handy here. Exercises provided are in classical cryptography, cryptanalysis, and selected coding schemes; these are useful in relating Python operations with characters effectively.