Добавьте один в колонку
In [110]:
numeric_cols = [col for col in df if df[col].dtype.kind != 'O']
numeric_cols
Out[110]:
['Gene1', 'Gene2', 'Gene3', 'Gene4']
In [111]:
df[numeric_cols] += 1
df
Out[111]:
Disease Gene1 Gene2 Gene3 Gene4
0 D1 1 1 26 1
1 D2 1 1 1 1
2 D3 1 18 1 17
3 D4 25 1 1 1
4 D5 1 1 1 1
5 D6 1 33 1 12
6 D7 1 1 1 1
7 D8 5 1 1 1
Elegant Elk