Need python help taking sum...

[jlandry287]

So what I'm trying to do is get the sum of quality points ("qp")

a=raw_input('Enter the number of courses you are taking: ')
print("")
print("")
b=int(a)
c=range(b)
if int(a) <= 0:
        print ('Error: You must have at least one class!')
d=('Enter the course *NAME*, *CREDITS*, and *GRADE*: ')

for i in range(b):
    locals()["y"+str(i)]=raw_input(d).split(',')
    locals()["p"+str(i)]=locals()["y"+str(i)][2]
    locals()["c"+str(i)]=locals()["y"+str(i)][1]
print("")
for i in c:
    if locals()["p"+str(i)]=='a':
        locals()["qp"+str(i)]=4
    elif locals()["p"+str(i)]=='b':
        locals()["qp"+str(i)]=3
    elif locals()["p"+str(i)]=='c':
        locals()["qp"+str(i)]=2
    elif locals()["p"+str(i)]=='d':
        locals()["qp"+str(i)]=1
    elif locals()["p"+str(i)]=='u':
        locals()["qp"+str(i)]=0
    else:
        print("You entered an incorrect grade!")
print("")
print("")
for i in c:
    gradesum=int(locals()["qp"+str(i)])
    k2=sum(gradesum)
    print k2
    
gpa= "dont know yet"
print("Your GPA is calculated to be: "+gpa)

[bvdet]

Creating a named variable for each value is a waste of resources. Manipulating locals() is generally a bad idea. I would suggest that you compile a list of user input and use a dictionary to translate letter grades to grade points. The following is untested. It uses a list comprehension to sum the grade points, but you could use a for loop just as well.

# b = number of courses taken

gradeDict = {"A": 4, "B": 3, "C": 2, "D": 1, "F": 0}
inputList = []

for i in range(b):
    while True:
        newdata = raw_input("Enter name, credits, and grade"
                            "('A'...'F') separated by commas")
        if newdata[-1].upper() not in gradeDict.keys():
            print "You entered an invalid grade. Try again."
        else:
            inputList.append(newdata.split(","))
            break

# Using dict method get() and a default value of 0 ensures the calculation
# does not fail due to a missing comma
GPA = sum([gradeDict.get(item[-1].upper(), 0) for item in inputList])/float(b)

[jlandry287]

ok i got it working, but it is not calculating correctly. How can i pull all of the "grades" and take the sum? that is the main part i'm having trouble with.

P.S., thanks for your insight, it works much cleaner

[bvdet]

I tried the code snippet below in my IDE.

>>> [gradeDict.get(item[-1].upper(), 0) for item in inputList]
[4, 2]
>>>