Combining.md

DataFrame.join()

• For pandas.DataFrame both join and merge operates on columns and rename common columns using parameter suffix
• concat can operate on columns or rows, depending on parameter axis and no renaming is performed.
• concat allow defining hierarchy structure by passing in parameters keys and names

how = 'left' | 'right' | 'inner' | 'outer'

• Combine all the columns from the two tables.
• Common columns are renamed with the paramaters lsuffix and rsuffix

DataFrame.join(self, 
               other, 
               on=None, 
               how='left', 
               lsuffix='', rsuffix='', 
               sort=False)

DataFrame.merge()

how = 'left' | 'right' | 'inner' | 'outer' | 'cross'

• Merge combines all the columns from two tables.
• Common columns can be renamed by parameter suffixes

Merge provide 3 ways to control alignment

1. on = 'ColumnName' ( Here the given column must be the common column in both tables )
2. left_on = 'ColumnName' and right_on = 'ColumnName' ( Tables are aligned using different columns )
3. left_index = True and right_index = True ( Tables are aligned based on their index )

# Starting with DataFrame:
DataFrame.merge(self, 
                right, 
                how='inner', 
                on=None, 
                left_on=None, right_on=None, 
                left_index=False, right_index=False, 
                sort=False, 
                suffixes=('_x', '_y'), 
                copy=True, 
                indicator=False, 
                validate=None)
                
# Starting with Pandas:                
pandas.merge(left, 
             right, 
             how='inner', 
             on=None, 
             left_on=None, right_on=None, 
             left_index=False, right_index=False, 
             sort=False, 
             suffixes=('_x', '_y'), 
             copy=True, 
             indicator=False, 
             validate=None)                

pandas.concat()

join = 'inner' | 'outer'

axis = 0 : Horizontally | Row Wise

axis = 1 : Vertically | Column Wise

pandas.concat(objs, 
              axis=0, # 0 for row and 1 for column
              join='outer', join_axes=None, 
              ignore_index=False, 
              keys=None, 
              levels=None, 
              names=None, 
              verify_integrity=False, 
              sort=None, 
              copy=True)