如何在 python 中使用循环 append

Question

I have been searching for hours. I have 190 columns of pivot table to loop on my script I have this script:

corr = pg.pairwise_corr(df_pvt, columns=[[df_pvt.columns[0]], list(df_pvt.columns)], method='pearson')[['X','Y','r']]

this provide output:

                                          X  ...      r
0    CORSEC_Mainstream Media_Negative Count  ...  1.000
1    CORSEC_Mainstream Media_Negative Count  ...  0.960
2    CORSEC_Mainstream Media_Negative Count  ... -0.203
3    CORSEC_Mainstream Media_Negative Count  ... -0.446
4    CORSEC_Mainstream Media_Negative Count  ...  0.488
..                                      ...  ...    ...
179  CORSEC_Mainstream Media_Negative Count  ... -0.483
180  CORSEC_Mainstream Media_Negative Count  ... -0.487
181  CORSEC_Mainstream Media_Negative Count  ...  0.145
182  CORSEC_Mainstream Media_Negative Count  ...  0.128
183  CORSEC_Mainstream Media_Negative Count  ...  0.520

[184 rows x 3 columns]

I want to append 189 other columns to my script, but this script keep providing 2 appended variables and keep replacing until the 189th variables

for var in list(range(1,189)):
    corr_all = corr.append(pg.pairwise_corr(df_pvt, columns=[[df_pvt.columns[var]], list(df_pvt.columns)], method='pearson')[['X','Y','r']])
    print(corr_all)

Any advice?

Edit:

Its work like this:

corr = pg.pairwise_corr(df_pvt, columns=[[df_pvt.columns[0]], list(df_pvt.columns)], method='pearson')[['X','Y','r']]
corr_1 = corr.append(pg.pairwise_corr(df_pvt, columns=[[df_pvt.columns[1]], list(df_pvt.columns)], method='pearson')[['X','Y','r']])
corr_2 = corr_1.append(pg.pairwise_corr(df_pvt, columns=[[df_pvt.columns[2]], list(df_pvt.columns)], method='pearson')[['X','Y','r']])

But how I loop it until the corr_189?

Answer 1

You can try making 189 lists of values (Pearson coefficients) for each of your 189 columns, and then concatenate the columns with " df_final " which would be the dataframe containing all the 190 columns:

corr = pd.DataFrame(corr)
df_final = pd.DataFrame()

for k in range(189):
    list_Pearson_k = 'formula to compute a list of pearson values'                    
    df_list_k = pd.DataFrame(list_Pearson_k)
    df_final = pd.concat([corr,df_list_k ], axis = 1) 

Answer 2

Python list append method returns None .

Change your code to this:-

corr_all = []
for var in range(1,189):
    corr_all.append(pg.pairwise_corr(df_pvt, columns=[[df_pvt.columns[var]], list(df_pvt.columns)], method='pearson')[['X','Y','r']])
    print(corr_all)

This should help.