- summarizing and computing descriptive statistics pandas objects are equipped with set of common mathematical and statistical methods most of these fall into the category of reductions or summary statisticsmethods that extract single value (like the sum or meanfrom series or series of values from the rows or columns of dataframe compared with the equivalent methods of vanilla numpy arraysthey are all built from the ground up to exclude missing data consider small dataframein [ ]df dataframe([[ np nan][ - ][np nannp nan][ - ]]index=[' '' '' '' ']columns=['one''two']in [ ]df out[ ]one two nan - nan nan - calling dataframe' sum method returns series containing column sumsin [ ]df sum(out[ ]one two - passing axis= sums over the rows insteadin [ ]df sum(axis= out[ ] nan - na values are excluded unless the entire slice (row or column in this caseis na this can be disabled using the skipna optionin [ ]df mean(axis= skipna=falseout[ ] nan nan - see table - for list of common options for each reduction method options summarizing and computing descriptive statistics www it-ebooks info