dropna threshold

#dropping columns having more than 50% missing values(1994/2==1000)
df=df.dropna(thresh=1000,axis=1)

>>> df.dropna(subset=['name', 'born'])
       name        toy       born
1    Batman  Batmobile 1940-04-25

# importing pandas as pd 
import pandas as pd 
  
# Creating the Index 
idx = pd.Index(['Jan', 'Feb', 'Mar', None, 'May', 'Jun', 
                None, 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']) 
  
# Print the Index 
idx