How to Combine DataFrames: Merging Values In One Column

There is a nice trick for showing two values in one cell in a data frame, which can provide a clearer view. For example, this can be useful when we want to show the values of a column and their ranks in a single cell.

Let’s suppose we have the following dataframe:

import pandas as pd
from IPython.display import display_html

df=pd.DataFrame({'A':[2.2,2.1,3.1,1.2,2.0],'B':[2.7,2.1,1.4,5.2,2.2]})

Let’s show how we can show both the values and the rank of these columns:

def combine_with_color(val1, val2):
    return f'<span style="color: red">{val1}</span>/<span style="color: blue">{val2}</span>'

combined = pd.DataFrame(index=df1.index, columns=df1.columns)
for col in df1.columns:
    combined[col] = [combine_with_color(df1.loc[idx, col], df2.loc[idx, col]) for idx in df1.index]

combined_html = combined.tail(30).to_html(escape=False)
display_html(combined_html, raw=True)

What we did was create an HTML representation of the values for every cell as shown below:

Then, using the to_html function of the pandas dataframe, we can transform it into HTML and show it using display_html.