print(a)
indices = [1, 5, -1]
b = a[indices]
print(b)
# where函数,返回使得条件为真的下标元素的列表...△ n.transpose()对换数组的维度,矩阵的转置
△ ndarray.T 与上类似,用于矩阵的转置
△ n.concatenate((a1, a2, ...), axis)沿指定轴连接同形数组...新建
import pandas as pd
a = pd.DataFrame([[1,2,3],
[4,5,6],
[7,8,9...dataframe
横向
pd.concat([a,a],axis=1)
纵向
pd.concat([a,a],axis=0)
数据去重
import pandas as pd
df = pd.DataFrame...copy
import pandas as pd
a = pd.DataFrame([[1,2,3],
[4,5,6],
[7,8,9