human
Write me a the Python program you requested given the following:
I am working on the file "PNTerms/Flux.ipynb".
The first task is:
Collected flux terms
Can you write Python program for it?
assistant
#Here is the Python program you requested.

def FluxExpression(FluxTerms=[Flux_NoSpin, Flux_Spin], PNOrder=frac(7,2)):
    # We have to play some tricks with the log terms so that `horner` works
    def logterm(key,val):
        if 'lnv2' in val:
            return logv**2
        if 'lnv' in val:
            return logv
        else:
            return 1
    return Fcal_coeff*horner(sum([key*(v**n)*logterm(key,val)
                                  for Terms in FluxTerms
                                  for n in range(2*PNOrder+1)
                                  for key,val in Terms.items()
                                  if val.endswith('_{0}'.format(n))])).subs(logv, ln(v))

# display(FluxExpression())