'''
Created on Oct 7, 2014

@author: Susan
'''
'''
Created on Oct 17, 2011

@author: rodger
'''


def processList(stringList):
    '''
    process the list of strings to 
    return a list of lists
    and remove the course number since it is not needed
    '''
    allLists = []
    for line in stringList:
        linelist = line.split()
        # remove course number
        allLists.append(linelist[1:])
    return allLists
        
        
def peopleTakingCourses(data):
    ''' data is a list of lists of names for each course,
    return list of all strings that appear at least once '''
    names = set([])
    for lista in data:
        seta = set(lista)
        names = names | seta
    return list(names)
    # return [w for w in names]
    
    
    
    
def peopleTakingOnlyOneCourse(data):
    ''' data is a list of lists of names for each course,
    returns list of people taking only one course '''
    names = set([])    
    listOfSets = [set(w)  for w in data]

    for index in range(len(listOfSets)):
        unionOtherCourses = unionAllSetsButMe(listOfSets, index)
        for person in listOfSets[index]:
            if person not in unionOtherCourses:
                names.add(person)
    return list(names)

        

# NOTE see setExampleSoln2.py for a solution that does not use enumerate    
def unionAllSetsButMe(allsets, me): 
    ''' allsets is a list of lists, me is the index number of
    one of the sets in allsets, returns the union of all the
    sets except the set in position me '''
    answer = set([])
    for (index,s) in enumerate(allsets):
        if index != me:
            answer = answer | s
    return answer
    
courseListsAll = ["compsci101 Smith Ye Li Lin Abroms Black", \
"math101 Green Wei Lin Yavatkar Delong Noell Ye Smith", \
"econ101 Abroms Curtson Williams Smith", \
"french1 Wills Wrigley Olson Lee", \
"history230 Black Wrigley Smith"]    

allcourses = processList(courseListsAll)
print allcourses

allpersons = peopleTakingCourses(allcourses)
allpersons.sort()
print str(len(allpersons)) + " people taking one or more courses"
print allpersons

allonecourse = peopleTakingOnlyOneCourse(allcourses)
allonecourse.sort()
print str(len(allonecourse)) + " people taking only one course"
print allonecourse