utah nan data alignment features are addressed as separate topic both the series object itself and its index have name attributewhich integrates with other key areas of pandas functionalityin [ ]obj name 'populationin [ ]obj index name 'statein [ ]obj out[ ]state california nan ohio oregon texas namepopulation series' index can be altered in place by assignmentin [ ]obj index ['bob''steve''jeff''ryan'in [ ]obj out[ ]bob steve jeff - ryan dataframe dataframe represents tabularspreadsheet-like data structure containing an ordered collection of columnseach of which can be different value type (numericstringbooleanetc the dataframe has both row and column indexit can be thought of as dict of series (one for all sharing the same indexcompared with other such dataframe-like structures you may have used before (like ' data frame)roworiented and column-oriented operations in dataframe are treated roughly symmetrically under the hoodthe data is stored as one or more two-dimensional blocks rather than listdictor some other collection of one-dimensional arrays the exact details of dataframe' internals are far outside the scope of this book while dataframe stores the data internally in two-dimensional formatyou can easily represent much higher-dimensional data in tabular format using hierarchical indexinga subject of later section and key ingredient in many of the more advanced data-handling features in pandas introduction to pandas data structures www it-ebooks info