import pandas as pd

d = {
    1: {'nombre': 'n1', 1: 10, 2: 20, 3: 30},
    2: {'nombre': 'n2', 1: 10, 2: 20, 3: 30},
    3: {'nombre': 'n3', 1: 11, 2: 21, 3: 30},
    4: {'nombre': 'n4', 1: 11, 2: 21, 3: 30},
    5: {'nombre': 'n5', 1: 12, 2: 22, 3: 30},
    6: {'nombre': 'n6', 1: 13, 2: 22, 3: 30},
    7: {'nombre': 'n7', 1: 14,        3: 35},
    8: {'nombre': 'n8',        2: 22, 3: 35},
}
pd.DataFrame.from_dict(d).transpose().set_index('nombre')

1    2   3
nombre
n1       10   20  30    # igual que n2
n2       10   20  30    # igual que n1
n3       11   21  30    # igual que n4
n4       11   21  30    # igual que n3
n5       12   22  30
n6       13   22  30
n7       14  NaN  35
n8      NaN   22  35

df[df.duplicated(keep=False)]

1   2   3
nombre
n1      10  20  30
n2      10  20  30
n3      11  21  30
n4      11  21  30