df.fillna(df.apply code example

Example 1: python pandas fillna

# importing pandas module
import pandas as pd  
# making data frame from csv file
nba = pd.read_csv("nba.csv")
  
# replacing na values in college with No college
nba["College"].fillna("No College", inplace = True)
# OR
nba.College.fillna("No College", inplace = True)
  
print(nba)

Example 2: fillna pandas inplace

When inplace = True , the data is modified in place, which means it will return nothing and the dataframe is now updated. When inplace = False , which is the default, then the operation is performed and it returns a copy of the object. You then need to save it to something.