Repeat and concatenate a DataFrame with constant step value increase-CodePudding

I have a dataframe like the following example:

   A  B  C   D   E   F
0  1  4  7  10  13  16
1  2  5  8  11  14  17
2  3  6  9  12  15  18

I want to repeat the all dataframe like it was one block, like I want to repeat the above dataframe 3 times and every element increases by 3 than the original one.

The desired dataframe:

   A   B   C   D   E   F
0  1   4   7  10  13  16
1  2   5   8  11  14  17
2  3   6   9  12  15  18
3  4   7  10  13  16  19
4  5   8  11  14  17  20
5  6   9  12  15  18  21
6  7  10  14  16  19  22
7  8  11  15  17  20  23
8  9  12  16  18  21  24

CodePudding user response：

res = pd.concat([df   3*i for i in range(3)], ignore_index=True)

Output:

>>> res

   A   B   C   D   E   F
0  1   4   7  10  13  16
1  2   5   8  11  14  17
2  3   6   9  12  15  18
3  4   7  10  13  16  19
4  5   8  11  14  17  20
5  6   9  12  15  18  21
6  7  10  13  16  19  22
7  8  11  14  17  20  23
8  9  12  15  18  21  24

Setup:

import pandas as pd

df = pd.DataFrame({
    'A': [1, 2, 3],
    'B': [4, 5, 6],
    'C': [7, 8, 9],
    'D': [10, 11, 12],
    'E': [13, 14, 15],
    'F': [16, 17, 18]
})

CodePudding user response：

Assuming df as input, use pandas.concat:

repeats = 3
step = 3
df2 = pd.concat([df i for i in range(0, len(df)*repeats, step)],
                ignore_index=True)

output:

   A   B   C   D   E   F
0  1   4   7  10  13  16
1  2   5   8  11  14  17
2  3   6   9  12  15  18
3  4   7  10  13  16  19
4  5   8  11  14  17  20
5  6   9  12  15  18  21
6  7  10  13  16  19  22
7  8  11  14  17  20  23
8  9  12  15  18  21  24