【Pandas】array轉DataFrame、DataFrame轉json、DataFrame修改列的順序

記錄在項目中遇到的一些問題。

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

對a進行轉置：

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

1、array轉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轉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轉jason
df_a_new = df_a.to_json(orient="columns")

3、DataFrame修改列的順序

在df_a中列的順序是a、b、c、d

現在需要的順序是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，贈送一個
拼接DataFrame，A,B,C, D四個DataFrame
ABCD = pd.concat([A,B,C, D], axis=1)

參考：
https://blog.csdn.net/qq_27328197/article/details/113823989