Python中dataframe\ array\ list相互转化

 import pandas as pd
 import numpy as np

 #创建列表
 a1=[1,2,3]

 #arange函数：指定初始值、终值、步长来创建数组
 a2=np.arange(0,1,0.1)

 #创建数据框
 a3=pd.DataFrame({'a':[1,2,3],'b':[4,5,6],'c':[7,8,9]})

#1、list 转化成array矩阵
b1 = np.array(a1).T
Out[30]: array([1, 2, 3])

　　

#2、array转化成dataframe
b2 = pd.DataFrame(a2)
Out[32]:
     0
0  0.0
1  0.1
2  0.2
3  0.3
4  0.4
5  0.5
6  0.6
7  0.7
8  0.8
9  0.9
b2.info()
<class 'pandas.core.frame.DataFrame'>
RangeIndex: 10 entries, 0 to 9
Data columns (total 1 columns):
0    10 non-null float64
dtypes: float64(1)
memory usage: 160.0 bytes

　　

#3、把Pandas中的dataframe转成numpy中的array
b3=a3.values

Out[35]:
array([[1, 4, 7],
       [2, 5, 8],
       [3, 6, 9]], dtype=int64)