Pandas styling Exercises: Write a Pandas program to highlight the negative numbers red and positive numbers black

Last update on May 02 2025 12:53:29 (UTC/GMT +8 hours)

1. Highlight Negative/Positive Values

Create a dataframe of ten rows, four columns with random values. Write a Pandas program to highlight the negative numbers red and positive numbers black.

Sample Solution :

Python Code :

import pandas as pd
import numpy as np
np.random.seed(24)
df = pd.DataFrame({'A': np.linspace(1, 10, 10)})
df = pd.concat([df, pd.DataFrame(np.random.randn(10, 4), columns=list('BCDE'))],
               axis=1)
print("Original array:")
print(df)
def color_negative_red(val):
    color = 'red' if val < 0 else 'black'
    return 'color: %s' % color
print("\nNegative numbers red and positive numbers black:")
df.style.applymap(color_negative_red)

Original array:

Original array:
      A         B         C         D         E
0   1.0  1.329212 -0.770033 -0.316280 -0.990810
1   2.0 -1.070816 -1.438713  0.564417  0.295722
2   3.0 -1.626404  0.219565  0.678805  1.889273
3   4.0  0.961538  0.104011 -0.481165  0.850229
4   5.0  1.453425  1.057737  0.165562  0.515018
5   6.0 -1.336936  0.562861  1.392855 -0.063328
6   7.0  0.121668  1.207603 -0.002040  1.627796
7   8.0  0.354493  1.037528 -0.385684  0.519818
8   9.0  1.686583 -1.325963  1.428984 -2.089354
9  10.0 -0.129820  0.631523 -0.586538  0.290720

Negative numbers red and positive numbers black:

Sample Output:

Download the Jupyter Notebook from here.

For more Practice: Solve these Related Problems:

Write a Pandas program to highlight negative values in red and positive values in black for a dataframe with random numbers.
Write a Pandas program to apply conditional styling that marks positive numbers black and negatives red, using a custom formatting function.
Write a Pandas program to color-code cells based on sign: red for negatives, black for zero and positives, and test it on a randomly generated dataframe.
Write a Pandas program to create a style function that highlights negative entries in a dataframe with red text while keeping positive numbers unchanged.

Go to:

Previous: Python Pandas Style Home.
Next: Create a dataframe of ten rows, four columns with random values. Convert some values to nan values. Write a Pandas program which will highlight the nan values.

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.