preliminaries what is this book aboutthis book is concerned with the nuts and bolts of manipulatingprocessingcleaningand crunching data in python it is also practicalmodern introduction to scientific computing in pythontailored for data-intensive applications this is book about the parts of the python language and libraries you'll need to effectively solve broad set of data analysis problems this book is not an exposition on analytical methods using python as the implementation language when say "data"what am referring to exactlythe primary focus is on structured dataa deliberately vague term that encompasses many different common forms of datasuch as multidimensional arrays (matricestabular or spreadsheet-like data in which each column may be different type (stringnumericdateor otherwisethis includes most kinds of data commonly stored in relational databases or tabor comma-delimited text files multiple tables of data interrelated by key columns (what would be primary or foreign keys for sql userevenly or unevenly spaced time series this is by no means complete list even though it may not always be obviousa large percentage of data sets can be transformed into structured form that is more suitable for analysis and modeling if notit may be possible to extract features from data set into structured form as an examplea collection of news articles could be processed into word frequency table which could then be used to perform sentiment analysis most users of spreadsheet programs like microsoft excelperhaps the most widely used data analysis tool in the worldwill not be strangers to these kinds of data www it-ebooks info