null values in each data set and remove

import pandas as pd
#import matplotlib.pyplot as plt
df=pd.read_csv('Downloads\Iris_null_values.csv')
print(df)
df.isnull().sum()
df[df['sepal.length'].isnull()]
df[df['sepal.width'].isnull()]
df.fillna('default')

import numpy as np

import pandas as pd

dict = {'First Column': [100, 90, None, 95],

   'Second Column': [30, 45, 56, 67], 

    'Third Column': [np.nan, 40, 80, 98]} 

df = pd.DataFrame(dict)

print (df)

df [df ['First Column'].isnull()]

df [df ['Second Column'].isnull()]

df [df ['Third Column'].isnull()]

df.dropna()