如何从DF中删除行，直到找到空行(Python)

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3, None, 5],
                   'B': [6, None, 8, 9, 10],
                   'C': [11, 12, 13, 14, 15]})

df = df.dropna(subset=['A', 'B', 'C'], how='all')

print(df)

import pandas as pd

df = pd.DataFrame({'A': [1, 2, 3, None, 5],
                   'B': [6, None, 8, 9, 10],
                   'C': [11, 12, 13, 14, 15]})

df = df.dropna(subset=['A', 'B', 'C'], how='all')

print(df)