How do i find a max value from an attribute with another attribute as an requirement in Python?

Question

I have this

How do i find max value of MMAX, but the vendor must be an "amdahl"?

Should I make a new data manually?
Use Python, pls..

score 2 · Answer 1 · answered Dec 20 '20 at 09:27

2

Try using groupby and max:

print(df.groupby('Vendor')['MMAX'].max()['amdahl'])

answered Dec 20 '20 at 09:27

U12-Forward

score 2 · Answer 2 · answered Dec 20 '20 at 09:39

2

You can also use loc:

print(max(df.loc[df['Vendor'] == 'amdahl'].MMAX))

answered Dec 20 '20 at 09:39

Ishan

MarianD · Answer 3 · 2020-12-20T11:02:25.483

df[df.Vendor == "amdahl"].MMAX.max()

The explanation:

df[df.Vendor == "amdahl"] selects only rows which fulfill the condition in brackets, then
.MMAX returns only the NMAX column (as a series), and finally
.max() method returns the maximum of that series values.

Note:

A more verbose version of the same approach is using the ["colname"] notations (instead of the abbreviated ones .colname):

df[df["Vendor"] == "amdahl"]["MMAX"].max()

3 Answers3