Pandas isnull(): Check Missing Values

The isnull() function in Python is a function within the pandas library used to check for missing values in data. Its specific usage is as follows:

import pandas as pd

# 创建一个包含缺失值的DataFrame
data = {'A': [1, 2, None, 4],
        'B': [None, 5, 6, 7]}
df = pd.DataFrame(data)

# 使用isnull()函数检查缺失值
print(df.isnull())

The output is as follows:

       A      B
0  False   True
1  False  False
2   True  False
3  False  False

The isnull() function will return a boolean DataFrame of the same dimensions as the original DataFrame, where True indicates that the corresponding value is missing, and False indicates that it is not missing.