df.loc[df['channel'].isin(['sale','fullprice'])]
>>> df.loc[(df["B"] > 50) & (df["C"] == 900), "A"]
2 5
3 8
Name: A, dtype: int64
>>> df.loc[(df["B"] > 50) & (df["C"] == 900), "A"].values
array([5, 8], dtype=int64)
>>> df.loc[(df["B"] > 50) & (df["C"] == 900), "A"] *= 1000
>>> df
A B C
0 9 40 300
1 9 70 700
2 5000 70 900
3 8000 80 900
4 7 50 200
5 9 30 900
6 2 80 700
7 2 80 400
8 5 80 300
9 7 70 800
df.loc[df['shield'] > 6]
max_speed shield
sidewinder 7 8