#333 Add columns with max min values grouped by values on the selected column using pandas

Jan 5, 2023 | pandas, python

table.txt

quad lcid eid fx fy fxy
QUAD 1 23 1.2 1.0 21.0
QUAD 4 24 2.6 2.0 22.0
QUAD 1 25 3.2 3.0 23.0
QUAD 2 23 4.6 4.0 24.0
QUAD 4 24 5.6 5.0 25.0
QUAD 2 25 6.2 6.0 26.0
QUAD 3 23 7.2 7.0 27.0
QUAD 3 24 6.2 8.0 28.0
QUAD 2 25 5.2 9.0 29.0
QUAD 4 23 3.3 10.0 30.0
QUAD 4 24 12.2 11.0 31.0
QUAD 1 25 1.1 12.0 32.0

ex333.py

import pandas as pd
df = pd.read_csv("table.txt", sep=" ")
print(df)
df['max fx'] = df.groupby('eid')['fx'].transform('max')
df['min fx'] = df.groupby('eid')['fx'].transform('min')
print(df)

output:

    quad  lcid  eid    fx    fy   fxy
0   QUAD     1   23   1.2   1.0  21.0
1   QUAD     4   24   2.6   2.0  22.0
2   QUAD     1   25   3.2   3.0  23.0
3   QUAD     2   23   4.6   4.0  24.0
4   QUAD     4   24   5.6   5.0  25.0
5   QUAD     2   25   6.2   6.0  26.0
6   QUAD     3   23   7.2   7.0  27.0
7   QUAD     3   24   6.2   8.0  28.0
8   QUAD     2   25   5.2   9.0  29.0
9   QUAD     4   23   3.3  10.0  30.0
10  QUAD     4   24  12.2  11.0  31.0
11  QUAD     1   25   1.1  12.0  32.0
    quad  lcid  eid    fx    fy   fxy  max fx  min fx
0   QUAD     1   23   1.2   1.0  21.0     7.2     1.2
1   QUAD     4   24   2.6   2.0  22.0    12.2     2.6
2   QUAD     1   25   3.2   3.0  23.0     6.2     1.1
3   QUAD     2   23   4.6   4.0  24.0     7.2     1.2
4   QUAD     4   24   5.6   5.0  25.0    12.2     2.6
5   QUAD     2   25   6.2   6.0  26.0     6.2     1.1
6   QUAD     3   23   7.2   7.0  27.0     7.2     1.2
7   QUAD     3   24   6.2   8.0  28.0    12.2     2.6
8   QUAD     2   25   5.2   9.0  29.0     6.2     1.1
9   QUAD     4   23   3.3  10.0  30.0     7.2     1.2
10  QUAD     4   24  12.2  11.0  31.0    12.2     2.6
11  QUAD     1   25   1.1  12.0  32.0     6.2     1.1