Getting wrong Results with my grading system

[mostwanted]

 I am getting wrong results with my grading system, i think this is more of a syntax problem, i just don't know where I'm mixing up things. My system is supposed to give students grades depending on what percentages they got but the grades do not correspond well with the percentages. I'm getting wrong grades for percentages, e.g 90% is supposed to give me grade 'A' but it is giving me grade 'B', they are all mixed up!!! Can someone assist please?! Thanks.

Here is my code:

{{extend 'layout.html'}}
..............
..............
..............
{{
         total=0
        for report in form:
        perc=(float(report.marks)/float(report.total))*float(100)
        if perc>=100:
            grade='A'
        elif perc>=79:
            grade='B'
        elif perc>=69:
            grade='C'
        elif perc>=59:
            grade='D'
        elif perc>=39:
            grade='E'
        elif perc>=19:
            grade='U'
        }}

{{pass}}
          {{
        total+=perc
        average=int(total/totalNum)
        if average>=100:
            avGrade='A'
        elif average>=79:
            avGrade='B'
        elif average>=69:
            avGrade='C'
        elif average>=59:
            avGrade='D'
        elif average>=39:
            avGrade='E'
        elif average>=19:
            avGrade='E'
        }}
        {{pass}}
        <tr>
            <td>{{=report.term.term}}</td>
            <td>{{=report.subject.subject_name}}</td>
        <td>{{=report.marks}}</td>
    <td>{{=report.total}}</td>
              <td>
{{=perc}}(%)
            </td>
            <td>{{=grade}}</td>
            </td>
        <td>{{=report.comments}}</td>
        </tr>


       {{pass}}
{{pass}}
    </table>
</div>
<div class="grades" style="margin-left: 5px;">
    <table>
        <tr>
            <th>AVERAGE</th>
            <th>TOTAL/GRADE</th>
            <th>CLASS/PS</th>
            <th>SCHOOL/PS</th>
        </tr>
        <tr>
            <td>{{=average}}(%)</td>
            <td>{{=avGrade}}</td>
            <td>3</td>
            <td>21</td>
        </tr>
    </table>

And I'd also be grateful if someone just simple explained what {{pass}} does in web2py and where do we place it because i find myself placing it in wrong places and at times it just disrupts the balance of the entire code if i don't place it correctly, that'd mean a lot, thanks.

[Kiran Subbaraman]

so if `perc >=90%, it is grade `A`? The code should reflect the same then. Right now, it is `A`, if `perc >= 100`, which is not a valid value for `perc`.
Am guessing the same is applicable for the `average` check too.

________________________________________
Kiran Subbaraman
http://subbaraman.wordpress.com/about/

On 18-Nov-17 1:37 PM, mostwanted wrote:

 I am getting wrong results with my grading system, i think this is more of a syntax problem, i just don't know where I'm mixing up things. My system is supposed to give students grades depending on what percentages they got but the grades do not correspond well with the percentages. I'm getting wrong grades for percentages, e.g 90% is supposed to give me grade 'A' but it is giving me grade 'B', they are all mixed up!!! Can someone assist please?! Thanks.

Here is my code:

{{extend 'layout.html'}}
..............
..............
..............
{{
         total=0
        for report in form:
        perc=(float(report.marks)/float(report.total))*float(100)
        if perc>=100:
            grade='A'
        elif perc>=79:
            grade='B'
        elif perc>=69:
            grade='C'
        elif perc>=59:
            grade='D'
        elif perc>=39:
            grade='E'
        elif perc>=19:
            grade='U'
        }}

{{pass}}
          {{
        total+=

perc
        average=int(average/totalNum)

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[Jose C]

Simple logic error...

Your first if clause should most likely be:

if perc >= 90:

in order to trap that value. 

[Anthony]

And I'd also be grateful if someone just simple explained what {{pass}} does in web2py and where do we place it because i find myself placing it in wrong places and at times it just disrupts the balance of the entire code if i don't place it correctly, that'd mean a lot, thanks.

The use of {{pass}} is explained here: http://web2py.com/books/default/chapter/29/05/the-views#The-views. Python usually defines code blocks based on indentation, but since the views do not require proper Python indentation, we need an alternate way to define code blocks when the boundaries are not otherwise obvious -- so you use {{pass}} to indicate the end of a code block. For example:

{{if some_condition:}}
This
{{else:}}
That
{{pass}}
Now we are outside the "else" block, so this line will always be displayed.

Without the {{pass}}, that last line would be part of the "else" block and therefore only display conditionally. Note, we do not need a {{pass}} at the end of the "if" block above, because the {{else:}} implies the end of the "if" block.

Typically, you would need a {{pass}} to indicate the end of an if, else, elif, or for block in a view.

Anthony

[mostwanted]

I want grade 'A' to fall within a range of percentages, 'A' ranges from 80%(being the lowest) to 100%(being the highest), how do i reflect that here to get the system to grade properly??

[mostwanted]

I want grade 'A' to fall within a range of percentages, 'A' ranges from 80%(being the lowest) to 100%(being the highest), how do i reflect that here to get the system to grade properly??

[mostwanted]

Thanks for the {{pass}} clarification, its clear now

[Anthony]

On Saturday, November 18, 2017 at 9:15:36 AM UTC-5, mostwanted wrote:

I want grade 'A' to fall within a range of percentages, 'A' ranges from 80%(being the lowest) to 100%(being the highest), how do i reflect that here to get the system to grade properly??

if perc >= 80:

The upper range doesn't matter, as presumably 100 is the maximum anyway.

Note, though, that you have defined a B as >= 79. That means that you get a B only if your percentage is between 79 and 80 -- once you hit 80, it's an A. Is that really what you want?

Anthony

[mostwanted]

What i want is to reflect an a 'A' if a student gets anything between 100% and 80%, hence the line

if perc>=100:
            grade='A'

and get grade 'B' if a student gets anything between79% and 70% hence the line

elif perc>=79:
            grade='B'
elif perc>=69:
            grade='C'

When i coded it i thought it's straight forward it'd reflect correctly but instead 70% gives me 'C' and 80% to 90% give me a 'B'!!!! I Cant figure out what I'm doing wrong where!

[黄祥]

think the answer is right in front of you (just a matter of conditional logic):

What i want is to reflect an a 'A' if a student gets anything between 100% and 80%, hence the line

if perc>=100:

grade='A'

pls try (not tested):

if perc>=80 and perc<=100:

grade='A'

and get grade 'B' if a student gets anything between79% and 70% hence the line

elif perc>=79:

grade='B'

pls try (not tested):

elif perc>=70 perc<=79:

grade='B'

best regards,

stifan

[Jose C]

This is starting to look like a homework assignment.  You do not seem to understand what the >= (greater than or equal to) means.

The python statement:

if perc >=100:
grade='A'

elif perc >= 79:
grade='B'
...

means or reads as (in English):  
if the value in 'perc' is greater than or equal to 100, then set the value of 'grade' to 'A'.  
Else if the value in perc is greater than or equal to 79 , then set the value of grade to 'B'.
Else if the value in perc is greater than or equal to 69, then set the value of grade to 'C'
and so on....

The above statements stop being evaluated after the first condition that is true.

Now can you see the error in the logic? If not, I would suggest you run through some sample values for perc using the above statements and see if that helps.

[mostwanted]

WOOOW!!! Thank you Jose i have been switching the signs, i have been using > as small than and <  as greater than,i do not know when all this information got mixed up in my head but it took your words to pay close attention & realize my error. Thank you.

And honestly its not a school assignment