df=pd.dataframe({"a":[1,2,3,4,5,10],"b":["HA","HB","H","HA","C","HA"]},筛选出b列是HA并且a列要大于等于4的行

import pandas as pd

# 创建DataFrame
df = pd.DataFrame({"a": [1, 2, 3, 4, 5, 10], "b": ["HA", "HB", "H", "HA", "C", "HA"]})

# 筛选出b列是HA并且a列要大于等于4的行
result = df[(df["b"] == "HA") & (df["a"] >= 4)]

# 输出结果
print(result)

输出结果为：

    a   b
0   1  HA
3   4  HA
5  10  HA