In this article, we will discuss how to highlight the NaN (Not a number) values in Pandas Dataframe. NaN values used to represent NULL values and sometimes it is the result of the mathematical overflow.
Lets first make a dataframe:
Python3
# Import Required Libraries import pandas as pd import numpy as np # Create a dictionary for the dataframe dict = {'Name': ['Sumit Tyagi', 'Sukritin', 'Akriti Goel', 'Sanskriti', 'Abhishek Jain'], 'Age': [22, 20, np.nan, np.nan, 22], 'Marks': [90, 84, 33, 87, 82]} # Converting Dictionary to Pandas Dataframe df = pd.DataFrame(dict) # Print Dataframe df |
Output:
Now, come to the highlighting part. Our objective is to highlight those cells which have Nan values.
Method 1: Highlighting Cell with nan values
We can do this by using the highlight_null() method of DataFrame.style property.This is a property that returns a Styler object, which has useful methods for formatting and displaying DataFrames. highlight_null() method requires one string parameter (the name of the colour with which you want to highlight the cell).
Example:
Python3
# Highlighting cell with nan values df.style.highlight_null('red') |
Output:
Method 2: Highlighting text with nan values instead of background
We can do this by using applymap() method of the style property. applymap() method requires a function that takes a scalar and returns a scalar.
Example:
Python3
# Highlighting text instead of the # cell's background df.style.applymap(lambda cell: 'color:red' if pd.isnull(cell) else '') |
Output:
Method 3: Highlighting the text of the complete row with nan values
We can do this using the apply() method
Example:
Python3
# Highlighting text of the complete row df.style.apply(lambda row: np.repeat('color: red' if row.isnull().any() else '', row.shape[0]), axis=1) |
Output:
Method 4: Highlighting the complete row with nan values
Python3
# Highlighting the complete row df.style.apply(lambda row: np.repeat('background: red' if row.isnull().any() else '', row.shape[0]), axis=1) |
Output:
Solution 5: Highlighting the whole column with nan values
Python3
# Highlighting column with nan values df.style.apply(lambda row: np.repeat('background: red' if row.isnull().any() else '', row.shape[0]), axis=0) |
Output:
