How to use the result.models.Session.objects.get function in result

def result_sheet_pdf_view(request, id):
    current_semester = Semester.objects.get(is_current_semester=True)
    current_session = Session.objects.get(is_current_session=True)
    result = TakenCourse.objects.filter(course__pk=id)
    no_of_pass = TakenCourse.objects.filter(course__pk=id, comment="PASS").count()
    no_of_fail = TakenCourse.objects.filter(course__pk=id, comment="FAIL").count()
    fname = str(current_semester) + '_semester_' + str(current_session) + '_session_' + 'resultSheet.pdf'
    fname = fname.replace("/", "-")
    flocation = '/tmp/'+fname

    doc = SimpleDocTemplate(flocation, rightMargin=0, leftMargin=6.5 * cm, topMargin=0.3 * cm, bottomMargin=0)
    styles = getSampleStyleSheet()
    styles.add(ParagraphStyle( name="ParagraphTitle", fontSize=11, fontName="FreeSansBold"))
    Story = [Spacer(1,.2)]
    style = styles["Normal"]

    logo = MEDIA_ROOT + "/logo/android-chrome-144x144.png"
    print(logo)
    im = Image(logo, 1*inch, 1*inch)

def semester_update_view(request, pk):
    semester = Semester.objects.get(pk=pk)
    if request.method == 'POST':
        if request.POST.get('is_current_semester') == 'True': # returns string of 'True' if the user selected yes for 'is current semester'
            unset_semester = Semester.objects.get(is_current_semester=True)
            unset_semester.is_current_semester = False
            unset_semester.save()
            unset_session = Session.objects.get(is_current_session=True)
            unset_session.is_current_session = False
            unset_session.save()
            new_session = request.POST.get('session')
            form = SemesterForm(request.POST, instance=semester)
            if form.is_valid():
            	set_session = Session.objects.get(pk=new_session)
            	set_session.is_current_session = True
            	set_session.save()
            	form.save()
            	messages.success(request, 'Semester updated successfully !')
            	return redirect('manage_semester')
        else:
            form = SemesterForm(request.POST, instance=semester)
            if form.is_valid():
                form.save()
                return redirect('manage_semester')

    else:
        form = SemesterForm(instance=semester)
    return render(request, 'result/semester_update.html', {'form': form})

def add_score(request):
    """ 
    Shows a page where a lecturer will select a course allocated to him for score entry.
    in a specific semester and session 

    """
    current_session = Session.objects.get(is_current_session=True)
    current_semester = get_object_or_404(Semester, is_current_semester=True, session=current_session)
    semester = Course.objects.filter(allocated_course__lecturer__pk=request.user.id, semester=current_semester)
    courses = Course.objects.filter(allocated_course__lecturer__pk=request.user.id).filter(semester=current_semester)
    context = {
    "courses": courses,
    }
    return render(request, 'result/add_score.html', context)

def course_registration_form(request):
    current_semester = Semester.objects.get(is_current_semester=True)
    current_session = Session.objects.get(is_current_session=True)
    courses = TakenCourse.objects.filter(student__user__id=request.user.id)
    fname = request.user.username + '.pdf'
    fname = fname.replace("/", "-")
    flocation = '/tmp/'+fname
    doc = SimpleDocTemplate(flocation, rightMargin=15, leftMargin=15, topMargin=0, bottomMargin=0)
    styles = getSampleStyleSheet()

    Story = [Spacer(1,0.5)]
    Story.append(Spacer(1,0.4*inch))
    style = styles["Normal"]

    style = getSampleStyleSheet()
    normal = style["Normal"]
    normal.alignment = TA_CENTER
    normal.fontName = "Helvetica"
    normal.fontSize = 12

def session_update_view(request, pk):
    session = Session.objects.get(pk=pk)
    if request.method == 'POST':
        a = request.POST.get('is_current_session')
        if a == '2':
            unset = Session.objects.get(is_current_session=True)
            unset.is_current_session = False
            unset.save()
            form = SessionForm(request.POST, instance=session)
            if form.is_valid():
                form.save()
                messages.success(request, 'Session updated successfully ! ')
        else:
            form = SessionForm(request.POST, instance=session)
            if form.is_valid():
                form.save()
                messages.success(request, 'Session updated successfully ! ')

def semester_update_view(request, pk):
    semester = Semester.objects.get(pk=pk)
    if request.method == 'POST':
        if request.POST.get('is_current_semester') == 'True': # returns string of 'True' if the user selected yes for 'is current semester'
            unset_semester = Semester.objects.get(is_current_semester=True)
            unset_semester.is_current_semester = False
            unset_semester.save()
            unset_session = Session.objects.get(is_current_session=True)
            unset_session.is_current_session = False
            unset_session.save()
            new_session = request.POST.get('session')
            form = SemesterForm(request.POST, instance=semester)
            if form.is_valid():
            	set_session = Session.objects.get(pk=new_session)
            	set_session.is_current_session = True
            	set_session.save()
            	form.save()
            	messages.success(request, 'Semester updated successfully !')
            	return redirect('manage_semester')
        else:
            form = SemesterForm(request.POST, instance=semester)
            if form.is_valid():
                form.save()
                return redirect('manage_semester')

def session_update_view(request, pk):
    session = Session.objects.get(pk=pk)
    if request.method == 'POST':
        a = request.POST.get('is_current_session')
        if a == '2':
            unset = Session.objects.get(is_current_session=True)
            unset.is_current_session = False
            unset.save()
            form = SessionForm(request.POST, instance=session)
            if form.is_valid():
                form.save()
                messages.success(request, 'Session updated successfully ! ')
        else:
            form = SessionForm(request.POST, instance=session)
            if form.is_valid():
                form.save()
                messages.success(request, 'Session updated successfully ! ')

    else:
        form = SessionForm(instance=session)
    return render(request, 'result/session_update.html', {'form': form})

def semester_add_view(request):
    if request.method == 'POST':
        form = SemesterForm(request.POST)
        if form.is_valid():
            data = form.data.get('is_current_semester') # returns string of 'True' if the user selected Yes
            if data == 'True':
            	semester = form.data.get('semester')
            	ss = form.data.get('session')
            	session = Session.objects.get(pk=ss)
            	try:
            		if Semester.objects.get(semester=semester, session=ss):
	            		messages.info(request, semester + " semester in " + session.session +" session already exist")
	            		return redirect('create_new_semester')
            	except:
	            	semester = Semester.objects.get(is_current_semester=True)
	            	semester.is_current_semester = False
	            	semester.save()
	            	form.save()
            form.save()
            messages.success(request, 'Semester added successfully ! ')
            return redirect('manage_semester')
    else:
        form = SemesterForm()
    return render(request, 'result/semester_update.html', {'form': form})