- - - - - the same interpolation methods available for reindexing can be used with fillnain [ ]df dataframe(np random randn( )in [ ]df ix[ : nadf ix[ : na in [ ]df out[ ] - nan nan - nan nan nan nan in [ ]df fillna(method='ffill'out[ ] - - - - in [ ]df fillna(method='ffill'limit= out[ ] - - nan - nan - with fillna you can do lots of other things with little creativity for exampleyou might pass the mean or median value of seriesin [ ]data series([ na na ]in [ ]data fillna(data mean()out[ ] see table - for reference on fillna table - fillna function arguments argument description value scalar value or dict-like object to use to fill missing values method interpolationby default 'ffillif function called with no other arguments axis axis to fill ondefault axis= inplace modify the calling object without producing copy limit for forward and backward fillingmaximum number of consecutive periods to fill getting started with pandas www it-ebooks info