📜  pandas 加入两个数据框 - Python (1)

📅  最后修改于: 2023-12-03 14:45:03.563000             🧑  作者: Mango

Introduction to Merging Two DataFrames in Pandas with Python

Pandas is a powerful data manipulation library in Python that provides easy-to-use data structures and data analysis tools. One of the tasks frequently performed while working with data is to merge two dataframes. This is where Pandas can be very useful.

Merging DataFrames

Merging dataframes involves combining two or more dataframes into a single dataframe. This can be done using the merge() function in Pandas. The merge function takes two dataframes and combines them into a single dataframe.

Here's a sample code that shows how to merge two dataframes in Pandas:

import pandas as pd
  
# Define two dataframes
df1 = pd.DataFrame({
    'key': ['A', 'B', 'C', 'D'],
    'value': [1, 2, 3, 4]
})
  
df2 = pd.DataFrame({
    'key': ['B', 'D', 'E', 'F'],
    'value': [5, 6, 7, 8]
})
  
# Merge the two dataframes
df_merged = pd.merge(df1, df2, on='key', how='inner')
  
print(df_merged)

In the above code snippet, we have defined two dataframes df1 and df2. We have then merged these two dataframes using the merge() function. In the merge() function, we have specified the joining column key, and the type of join as inner.

The resulting merged dataframe will contain only rows that have matching values in both dataframes for the column key.

Conclusion

In this article, we have learned how to merge two dataframes in Pandas using the merge() function. It is a very powerful tool that enables us to combine datasets in a seamless manner. Pandas is an essential library for data manipulation and analysis, and mastering it can help to make data-related tasks more efficient and effective.