python - 查找给定温度范围内数组中的最大值

Question

Study   Gas Surfactant  Surfactant Concentration    Additive    Additive 

Concentration   LiquidPhase Quality Pressure (Psi)  Temperature (C)     Shear Rate (/Sec)   Halflife (Min)  Viscosity   Color
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   51  0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   61  0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   75  0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   105 0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   12  0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   25  0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   34  0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  50  0   48  0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  100 0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  100 0   0.1 0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  100 0   0.5 0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  100 0   0.79    0   yellow
Thakore 2020    N2  AOS 1 w%    None    None    DI Water    0.95    10  100 0   0.9 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  50  0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  50  0   26  0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  50  0   72  0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  50  0   84  0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  50  0   120 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0.33    0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   1   0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   1.9 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   2.4 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0.2 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   1   0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   1.3 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   1.9 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0.1 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0.2 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0.26    0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  100 0   0.3 0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  150 0   0   0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  150 0   0.05    0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  150 0   0.08    0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  150 0   0.13    0   yellow
Thakore 2020    N2  AOS 1 w%    Guar    0.36 w% DI Water    0.95    10  150 0   0.2 0   yellow

上面显示的是我的数组的示例。如何找到给定温度下“半衰期”的最大值？假设我想从每个温度为 25 度的元素中找到“半衰期”的最大值。有没有一种优雅的方法来做到这一点？

我尝试在 for 循环中循环，将温度分成单独的列表，然后使用大量 if 语句，找到每个列表的最大值并将其编译回主列表中。这非常丑陋且耗时，我想知道是否有更好的方法来做到这一点。请告诉我!

基本上，我将 Excel 文件加载到 pandas 数据框中:

dv = pd.read_excel('data.xlsx')

然后我清理它并将其重命名为“cleaned”，这并不重要，只是提一下。

ahmed17 = cleaned[cleaned.Study == "Ahmed 2017"]
ahmed18 = cleaned[cleaned.Study == "Ahmed 2018"]
alzo = cleaned[cleaned.Study == "Alzobaidi 2017"]
reid = cleaned[cleaned.Study == "Reidenbach 1986"]
har = cleaned[cleaned.Study == "Harris 1987"]
chen = cleaned[cleaned.Study == "Chen, Y. 2016b"]
yan = cleaned[cleaned.Study == "Yanqing Wang 2017"]
hut = cleaned[cleaned.Study == "Hutchins 2005"]
tha = cleaned[cleaned.Study == "Thakore 2020"]
ha = cleaned[cleaned.Study == "Harris 1995"]

从那里，我将清理后的数据框分成单独的研究，这个项目是文献的组成。

trace1 = go.Scatter(y=ahmed17[selected_y], x=ahmed17[selected_x])

最后，我将每个单独的研究加载到迹线中，并将它们显示在图表中。选定的 y 和选定的 x 是字符串，例如“Temperature (C)”和“Halflife (Min)”。

我需要做的是，在将数组拆分为单独的研究之前，找到相对于每个温度(0,50,100,150,200,250,300)的最大“半衰期”并将它们编译成单独的列表，然后将它们编译成同一个列表。从那里我可以将列表分成单独的研究，然后我就可以开始了。我尝试使用以下内容来做到这一点:

tha25 = [x for x in tha[selected_x] if x == 25]

将 thakore 研究分成 25 度列表，然后从那里找到最大值。但我得到了我编译的列表的一堆 Nan 值，并且我不确定我是否正确地拆分了列表。

Answer 1

如果您的原始、清理后的数据框是 df，请尝试以下操作:

(df[df['Temperature']==25])['Halflife'].max()