How to combine dataframes in Pandas?

To combine dataframes in Pandas, we will show some examples. We can easily combine DataFrames or even Series in Pandas. Pandas is an open-source Python Library providing high-performance data manipulation and analysis tool using its powerful data structures. A Data frame is a two-dimensional data structure, i.e., data is aligned in a tabular fashion in rows and columns.

Combine DataFrames using Inner Join

Example

Let us combine the dataframes using inner join in Python

import pandas as pd

# Create Dictionaries
dct1 = {'Player':['Jacob','Steve','David','John','Kane'], 'Age':[29, 25, 31, 26, 27]}
dct2 = {'Rank':[1,2,3,4,5], 'Points':[100,87, 80,70, 50]}

# Create DataFrame from Dictionary elements using pandas.dataframe()
df1 = pd.DataFrame(dct1)
df2 = pd.DataFrame(dct2)
print("DataFrame1 = \n",df1)
print("\nDataFrame2 = \n",df2)

# Combining DataFrames using inner join
res = pd.concat([df1, df2], axis=1, join='inner')
print("\nCombined DataFrames = \n",res)

Output

DataFrame1 = 
Player     Age
0  Jacob   29
1  Steve   25
2  David   31
3   John   26
4   Kane   27

DataFrame2 = 
Rank  Points
0     1     100
1     2      87
2     3      80
3     4      70
4     5      50
Combined DataFrames = 
Player     Age  Rank  Points
0  Jacob   29     1     100
1  Steve   25     2      87
2  David   31     3      80
3   John   26     4      70
4   Kane   27     5      50

Combine DataFrames using append()

Example

In this example, we will us combine the dataframes using append() in Python

import pandas as pd

# Create Dictionaries
dct1 = {'Player':['Steve','David'], 'Age':[29, 25,]}
dct2 = {'Player':['John','Kane'], 'Age':[31, 27]}

# Create DataFrame from Dictionary elements using pandas.dataframe()
df1 = pd.DataFrame(dct1)
df2 = pd.DataFrame(dct2)
print("DataFrame1 = \n",df1)
print("\nDataFrame2 = \n",df2)

# Combining DataFrames using append()
res = df1.append(df2)
print("\nCombined DataFrames = \n",res)

Output

DataFrame1 = 
Player     Age
0  Steve   29
1  David   25

DataFrame2 = 
   Player  Age
0   John   31
1   Kane   27

Combined DataFrames = 
Player     Age
0  Steve   29
1  David   25
0   John   31
1   Kane   27

Combine DataFrames using concat()

Example

In this example, we will us combine the dataframes using concat() in Python −

import pandas as pd

# Create Dictionaries
dct1 = {'Player':['Steve','David'], 'Age':[29, 25,]}
dct2 = {'Player':['John','Kane'], 'Age':[31, 27]}

# Create DataFrame from Dictionary elements using pandas.dataframe()
df1 = pd.DataFrame(dct1)
df2 = pd.DataFrame(dct2)
print("DataFrame1 = \n",df1)
print("\nDataFrame2 = \n",df2)

# Combining DataFrames using concat()
res = pd.concat([df1, df2])
print("\nCombined DataFrames = \n",res)

Output

DataFrame1 = 
Player     Age
0  Steve   29
1  David   25DataFrame2 = 
Player     Age
0   John   31
1   Kane   27
Combined DataFrames = 
Player     Age
0  Steve   29
1  David   25
0   John   31
1   Kane   27