Why is the Abaqus python script not printing the correct maximum stress from the element set?

Question

I want to use abaqus python scripting to extract and print the maximum von Mises stress and the associated element of specific element sets at each step from ODB files. This would be extracting the maximum stress from the last frame of first few steps, and from all the frames in the last step.

I used the the example from the Abaqus documentation and modified it by using an if-else statement in a for loop. However, the script is not always giving me the correct max stress for the initial steps (i.e. when IF is true). It appears to print the answer for the first element within elemset without running through all the other elements. Any help would be greatly appreciated, thanks!

mySteps = odb.steps
numSteps = len(mySteps)
lastStep = numSteps - 1
#
#Initialize maximum values
maxMises = -0.1
maxElem = 0
maxStep = "_None_"
maxFrame = -1
Stress = 'S'
for i in range(numSteps):
    stepKey = mySteps.keys()[i]
    step = mySteps[stepKey]
    lastFrame = len(step.frames) - 1
    
    if i < lastStep:
        allFields = step.frames[lastFrame].fieldOutputs
        stressSet = allFields[Stress].getSubset(region=elemset)
        for stressValue in stressSet.values:
            if maxMises <= stressValue.mises:
                    maxMises = stressValue.mises
                    maxElem = stressValue.elementLabel
                    maxStep = step.name
                    maxFrame = step.frames[lastFrame].incrementNumber
    else:
        for frame in step.frames:
            allFields = frame.fieldOutputs
            stressSet = allFields[Stress].getSubset(region=elemset)
            for stressValue in stressSet.values:
                    if maxMises <= stressValue.mises:
                        maxMises = stressValue.mises
                        maxElem = stressValue.elementLabel
                        maxStep = step.name
                        maxFrame = frame.incrementNumber
    print 'Maximum von Mises stress %s is %f in element %d'%(
        region, maxMises, maxElem)
    print 'Location: frame # %d  step:  %s '%(maxFrame,maxStep)
    maxMises = -0.1
    maxElem = 0