How can I sum values with same column and row

Question

I have four matrices. I structured it with Panda with column and row names. I want to sum four matrices with the same row and column name to get 8x8 matrix. To make it clear;

Matrix 1: row 1 column 1 -> 1

Matrix 3: row 1 column 1 -> 0.64

I want to sum only 1 and 0.64. So in my new 8x8 matris row 1 column 1 -> 1.64

Sorry for my weak English. I hope you understand.

I tried if condition but I couldn't make up a good if condition.

matris = pd.DataFrame(matris, columns=column_names, index=row_names)

Click to access my matric structure

Answer 1

You can use the add method (see here ) because it allows "addition of dataframe and other, element-wise".

Thus, if your four DataFrameare named df1, df2, df3 and df4, you can add them up in this way:

df1.add(df2.add(df3.add(df4)))

if all the dataframes have the same indexes and columns, that will work perfectly for you. Otherwise, you could just make a sum of the values of each DataFrame:

df1.values + df2.values + df3.values + df4.values

Such solution will work nicely if all the DataFrames have the same shape, regardless if they different column names and/or index labels.