import arcpy
from arcpy.sa import *
arcpy.env.workspace = "F:/SED/T1"

past = arcpy.ListRasters("*1961-1990_RCP4.5*", "ASC")
future1 = arcpy.ListRasters("*2041-2060_RCP4.5*", "ASC")
future2 = arcpy.ListRasters("*2061-2080_RCP4.5*", "ASC")
future3 = arcpy.ListRasters("*2081-2100_RCP4.5*", "ASC")

for p, f1, f2, f3 in zip(past, future1, future2, future3):
    Minuspf1 = arcpy.Minus_3d(p ,f1)
    Minuspf2 = arcpy.Minus_3d(p ,f2)
    Minuspf3 = arcpy.Minus_3d(p ,f3)

    Max1 = float(arcpy.GetRasterProperties_management(Minuspf1,"MAXIMUM").getOutput(0))
    Max2 = float(arcpy.GetRasterProperties_management(Minuspf2,"MAXIMUM").getOutput(0))
    Max3 = float(arcpy.GetRasterProperties_management(Minuspf3,"MAXIMUM").getOutput(0))

    print(Max1)
    print(Max2)
    print(Max3)

    SED1 = Power(Divide(Minuspf1, Max1), 2)
    SED2 = Power(Divide(Minuspf2, Max2), 2)
    SED3 = Power(Divide(Minuspf3, Max3), 2)