Jython -Python how to return different parts of string to get grades

Question

how would i go about using strings and splits to be able to get a certain grade from three different grades for a specific person out of three in the list. This is the list. Justin:Calculus$90:Java$85:Python$88: Taylor:Calculus$73:Java$95:Python$86: Drew:Calculus$80:Java$75:Python$94: I am currently stuck with this. The best example I can find was this.

def phonebook():
  return """
Mary:893-0234:Realtor:
Fred:897-2033:Boulder crusher:
Barney:234-2342:Professional bowler:"""

def phones():
  phones = phonebook()
  phonelist = phones.split('\n')
  newphonelist = []
  for list in phonelist:
    newphonelist = newphonelist + [list.split(":")]
  return newphonelist
def findPhone(person):
  for people in phones():
    if people[0] == person:
      print "Phone number for",person,"is",people[1]

as you can see. the problem with this is it only returns both the phone number and their title. what I needed to do was to return only name and grade of a class along with the class with only 2 inputs (name,subject). here is what i have so far.

def scoreList():
 return"""
  Justin:Calculus$90:Java$85:Python$88:
  Taylor:Calculus$73:Java$95:Python$86:
  Drew:Calculus$80:Java$75:Python$94:"""
def scores():
  scores=scoreList()
  scorelist=scores.split('\n')
  newscorelist=[]
  for list in scorelist:
   newscorelist=newscorelist + [list.split(":")]
   scores.split('$')
  return newscorelist
def findScore(student,subject):
  for people in scores():
   for subject in scores():
    if people[0]==student:
     if subject[0]==subject:
      print (student,"got",score,"of the course",subject[1])

and yes, I am a novice at this. I've been searching for how to do this for days now though.

Does the data really look like that? Where is it coming from or is this just an exercise? — RussW, Jul 23 '13 at 19:33

Matthew Wesly · Answer 1 · 2013-07-23T17:01:10.517

I would suggest using a dictionary of dictionaries.

First create your dictionary

students = {}

now for each line, create a student

for studentdata in scores.split('\n'):
    data = studentdata.split(':')
    name = data[0]
    students[name] = {}

now add each class as a key in the student dictionary

for class_data in data[1:]:
    if class_data:
        class_name,class_score = class_data.split('$')
        students[name][class_name] = class_score

putting it all together you get:

students = {}
for studentdata in scores.split('\n'):
    data = studentdata.split(':')
    name = data[0]
    students[name] = {}
    for class_data in data[1:]:
        if class_data:
            class_name,class_score = class_data.split('$')
            students[name][class_name] = class_score

students is now an dictionary of dictionary. To find scores relating to a student now findScore is:

def findScore(student,subject):
    print "student %s got %s of the course %s" % (student,students[student][subject],subject)

it is not guaranteed that student and subject are in the dictionaries, if they are not an error will occur. To prevent this, simply check if that key is in the dictionary:

def findScore(student,subject):
    if student in students:
        if subject in students[student]:
            print "student %s got %s of the course %s" % (student,students[student][subject],subject)
        else:
            print "subject %s not found for student %s" % (subject,student)
    else:
        print "student %s not found" % (student)

Now really putting it all together you get:

scores = """Justin:Calculus$90:Java$85:Python$88:
Taylor:Calculus$73:Java$95:Python$86:
Drew:Calculus$80:Java$75:Python$94:"""

students = {}
for studentdata in scores.split('\n'):
    data = studentdata.split(':')
    name = data[0]
    students[name] = {}
    for class_data in data[1:]:
        if class_data:
            class_name,class_score = class_data.split('$')
            students[name][class_name] = class_score

def findScore(student,subject):
    if student in students:
        if subject in students[student]:
            print "student %s got %s of the course %s" % (student,students[student][subject],subject)
        else:
            print "subject %s not found for student %s" % (subject,student)
    else:
        print "student %s not found" % (student)

#do some testing
findScore("Bob","Painting")
findScore("Taylor","Painting")
findScore("Taylor","Calculus")

Some more information on dictionaries (as well as other data structures) can be found here

thanks alot, but this returns something a little wrong. when my input was findScore("Justin","Java") it gave me "student Justin got Java of the course 85" — user2611288, Jul 23 '13 at 16:42
Also, there is information on formatting strings [here](http://stackoverflow.com/questions/997797/python-and-s) if you want to change what it prints. — Matthew Wesly, Jul 23 '13 at 17:03
sorry for the late response but, it was a quick fix for me yesterday. thanks a lot. I just couldnt find examples to show me how to work the 2 splits to get different parts as a result the final def findScore was ran. — user2611288, Jul 24 '13 at 14:48

Jython -Python how to return different parts of string to get grades

1 Answers1