如何判断DataFrame中是否有缺失值NaN？

ref: https://blog.csdn.net/chenpe32cp/article/details/78398090

import pandas as pd
import numpy as np

df = pd.DataFrame(np.random.randn(10,6))
# Make a few areas have NaN values
df.iloc[1:3,1] = np.nan
df.iloc[5,3] = np.nan
df.iloc[7:9,5] = np.nan
print(df)
print(df.isnull().any()) #用来判断某列是否有缺失值
# df.isnull().all() #用来判断某列是否全部为空值

输出：