How do I get my python function to properly apply an IF-ELIF-ELSE statements correctly to all rows in my pandas dataframe?

I am trying to calculate the CGPA of a number of students. The idea here is that each student takes N courses (in this case, N = 3). Every course has its course load which is an integer and can range from 1 to 6. At the end of the semester, the CGPA is calculated based on the unit load of all the courses taken by each student and the grades obtained.

I am trying to do this using a for statement to loop through the entire dataset a row at a time and then an if suite to determine the number of units to assign to each student according to the grade scored. The problem here is that the code works but it doesn't follow through. So if the first student in the dataframe had an A in course1, the code gives him 15units and all other students also get 15units irregardless of if they score a D or an F.

I really want to know what I am doing wrong and how I can fix it. I would also appreciate it if you can suggest smarter ways of accomplishing this task. Thanks.

I have added breaks in the first course section but I am afraid the code is still not generalizing well.

A = 5; B = 4; C = 3; D = 2; E = 1; F = 0;
course1_cl = 3; course2_cl = 3; course3_cl = 3

def calculate_CGPA(dataframe, a, b, c, d):
    for row in dataframe[d]:
        if dataframe[a].any()=='A':
            dataframe['units'] = A * course1_cl
            break
        elif dataframe[a].any()=='B':
            dataframe['units'] = B * course1_cl
            break
        elif dataframe[a].any()=='C':
            dataframe['units'] = C * course1_cl
            break
        elif dataframe[a].any()=='D':
            dataframe['units'] = D * course1_cl
            break
        elif dataframe[a].any()=='E':
                dataframe[units] = E * course1_cl
        else:
            dataframe[units]= 0 
    print("Done generating units for: "+ format(a))
    for row in dataframe[d]:
        if dataframe[b].any()=='A':
            dataframe['units2']=A * course2_cl
        elif dataframe[b].any()=='B':
            dataframe['units2'] = B*course2_cl
        elif dataframe[b].any()=='C':
            dataframe['units2'] = C*course2_cl
        elif dataframe[b].any()=='D':
            dataframe['units2'] = D*course2_cl
        elif dataframe[b].any()=='E':
            dataframe['units2'] = E*course2_cl
        else:
            dataframe['units2'] = 0 
    print("Done generating units for: "+format(b))

    for row in dataframe[d]:
        if dataframe[c].any()=='A':
            dataframe['units3']= A * course3_cl
        elif dataframe[c].any()=='B':
            dataframe['units3'] = B*course3_cl
        elif dataframe[c].any()=='C':
            dataframe['units3'] = C*course3_cl
        elif dataframe[c].any()=='D':
            dataframe['units3'] = D*course3_cl
        elif dataframe[c].any()=='E':
            dataframe['units3'] = E*course3_cl
        else:
            dataframe['units3'] = 0
    print("Done generating units for: "+format(c))

    df['CGPA'] = (dataframe['units'] + dataframe['units2'] + dataframe['units3'])/(course1_cl + course2_cl + course3_cl)

The resulting dataframe should have 4 newly added columns: One units column for each of the three courses and a CGPA column as seen below. The values in the units and CGPA columns should change dynamically based on the grades scored by the individual.

S/N,Name,ExamNo,Course1,Course2,Course3,Units,Units2,Units3,CGPA

1,Mary Beth,A1,A,A,B,15,15,12,4.67

2,Elizabeth Fowler,A2,B,A,A,12,15,15,4.67

3,Bright Thompson,A12,C,C,B,9,9,12,3.33

4,Jack Daniels,A24,C,E,C,9,3,9,2.33

5,Ciroc Brute,A31,A,B,C,15,12,9,4.0