Text Parsing in Python

Text parsing is a common programming task that splits the given sequence of characters or values (text) into smaller parts based on some rules. It has been used in a wide variety of applications ranging from simple file parsing to large scale natural language processing.

Based on the context, different methodologies can be used such as parsing line by line using python's native string methods, using specialized pattern recognition language like regular expressions, using lex and yacc where the given sequence is analyzed, tokenized and the grammar is determined. This talk focuses on how and when to use different text parsing methods.

Most of the software applications require parsing at some point of time. It would be better to know, what kind of parsing gives the best results based on different contexts like recognizing some characters in predefined structures, retrieving some messages from the given data, Natural Language Processing etc. At some places RE's are more efficient than string functions and in some other context Lex and Yacc works better and vice-versa. This talk gives an idea about different ways of parsing and their efficiency with respect to the requirement. Below is the rough outline of the topics that will be discussed.

• What is parsing?
• Why parsing?
• Parsing in python
• Simple string functions
• Regular expressions
• Lex and yacc
• Efficient and appropriate use of different techniques

Gayatri is working in Infotech Enterprises Limited, Hyderabad. She has four years of python programming experience in developing desktop applications and is familiar with web development.

Madhubala is working in Infotech Enterprises Limited, Hyderabad. She has six years of python programming experience in developing desktop applications and simulation tools.