【Pandas】array转DataFrame、DataFrame转json、DataFrame修改列的顺序

记录在项目中遇到的一些问题。

import numpy as np

a = np.array((0.2,0.5,0.9,1.5))

对a进行转置：

import numpy as np

a = np.array((0.2,0.5,0.9,1.5))
a_new = a.reshape(1,4)

1、array转DataFrame

import numpy as np
import pandas as pd

a = np.array((0.2,0.5,0.9,1.5))
a_new = a.reshape(1,4)

df_a = pd.DataFrame(a_new)

修改列名：

import numpy as np
import pandas as pd

a = np.array((0.2,0.5,0.9,1.5))
a_new = a.reshape(1,4)


df_a = pd.DataFrame(a_new)

df_a.columns = ['a', 'b', 'c', 'd'] # 列名

2、DataFrame转json

import numpy as np
import pandas as pd

a = np.array((0.2,0.5,0.9,1.5))
a_new = a.reshape(1,4)
df_a = pd.DataFrame(a_new)
df_a.columns = ['a', 'b', 'c', 'd'] # 列名
# DataFrame转jason
df_a_new = df_a.to_json(orient="columns")

3、DataFrame修改列的顺序

在df_a中列的顺序是a、b、c、d

现在需要的顺序是d、b、c、a

import numpy as np
import pandas as pd

a = np.array((0.2,0.5,0.9,1.5))
a_new = a.reshape(1,4)
df_a = pd.DataFrame(a_new)
df_a.columns = ['a', 'b', 'c', 'd'] # 列名

df_a_p = df_a[["d","b","c","a"]]

附，赠送一个
拼接DataFrame，A,B,C, D四个DataFrame
ABCD = pd.concat([A,B,C, D], axis=1)

参考：
https://blog.youkuaiyun.com/qq_27328197/article/details/113823989