例2.41DataFrame数据操作示例
import pandas as pd
import numpy as np
a = pd.DataFrame(np.random.randint(1,6,(5,3)),
index=['a','b','c','d','e'],
columns=['one','two','three'])
a.loc['a','one'] = np.nan
b = a.iloc[1:3,0:2].values
a['four'] = 'bar'
a2 = a.reindex(['a','b','c','d','e','f'])
a3 = a2.dropna()
print("学号：3008")结果如下
