Joining pandas DataFrames by Column names

by

You can use the left_on and right_on options of pd.merge as follows:

pd.merge(frame_1, frame_2, left_on='county_ID', right_on='countyid')

Or equivalently with DataFrame.merge:

frame_1.merge(frame_2, left_on='county_ID', right_on='countyid')

I was not sure from the question if you only wanted to merge if the key was in the left hand DataFrame. If that is the case then the following will do that (the above will in effect do a many to many merge)

pd.merge(frame_1, frame_2, how='left', left_on='county_ID', right_on='countyid')

Or

frame_1.merge(frame_2, how='left', left_on='county_ID', right_on='countyid')

More Related Contents:

  1. Filter pandas DataFrame by substring criteria
  2. Binning a column with Python Pandas
  3. Compare two DataFrames and output their differences side-by-side
  4. Selecting a row of pandas series/dataframe by integer index
  5. How do I find the closest values in a Pandas series to an input number?
  6. How do I transpose dataframe in pandas without index?
  7. How to select all columns whose names start with X in a pandas DataFrame
  8. Remove reverse duplicates from dataframe
  9. How do I count the NaN values in a column in pandas DataFrame?
  10. How to split text in a column into multiple rows
  11. getting the index of a row in a pandas apply function
  12. How to flatten a pandas dataframe with some columns as json?
  13. Tilde sign in pandas DataFrame
  14. Pandas merge two dataframes with different columns
  15. Pandas filter dataframe rows with a specific year
  16. Python Pandas How to assign groupby operation results back to columns in parent dataframe?
  17. In Pandas, does .iloc method give a copy or view?
  18. Convert Pandas Series to DateTime in a DataFrame
  19. Python – Delete duplicates in a dataframe based on two columns combinations?
  20. Why is np.where faster than pd.apply
  21. Extract column value based on another column in Pandas
  22. Change the color of text within a pandas dataframe html table python using styles and css
  23. Scraping dynamic data selenium – Unable to locate element
  24. Convert list into a pandas dataframe
  25. Python Pandas: Convert “.value_counts” output to dataframe
  26. Remove substring from column based on another column
  27. Python: How to drop a row whose particular column is empty/NaN?
  28. Combine Pandas data frame column values into new column
  29. DataFrame object has no attribute append
  30. Python Pandas : pandas.to_datetime() is switching day & month when day is less than 13

Leave a Comment