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Pandas DataFrame combine() Method

❮ DataFrame Reference


Combine two DataFrames columnwise, and return the largest column:

import pandas as pd

df1 = pd.DataFrame([[1, 2], [3, 4]])
df2 = pd.DataFrame([[5, 6], [7, 8]])

def myfunc(a, b) :
  if (a.sum() > b.sum()):
    return a
    return b

print(df1.combine(df2, myfunc))
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Definition and Usage

The combine() method combines two DataFrame objects, and uses a specified function two decide which column to keep.


dataframe.combine(other, func, fill_value, overwrite)


The fill_value and overwrite parameters are keyword arguments.

Parameter Value Description
other   Required. A DataFrame.
func   Required. A function that will compare the columns and return one of them.
fill_value Number|None Optional. Default None. A value to fill empty cells with.
overwrite True|False Optional. Default True. Specify whether columns that do not exists in the second DataFrame will be overwritten (with NaN) or not

Return Value

A DataFrame with the results.

❮ DataFrame Reference