gistfile1.py

import sys
f = open('students.csv').read()
while f.split('\n')[0] != 'name,email':
    morecsv = raw_input("This does not look like the correct file. Would you like to see more? y/n?")
    while morecsv != 'y' and 'n':
        morecsv = raw_input("The prompt was y/n only. Would you like to see more? y/n?")
    if morecsv == 'y':
        print f.split('\n')[:10]
        newcsv = raw_input("Would you like to overwrite this file to create the student list? y/n?")
        while newcsv != 'y' and 'n':
            newcsv = raw_input("y/n only. Would you like to overwrite this file to create the student list?")
        if newcsv == 'y':
            newfile = open('students.csv','w')
            newfile.truncate()
            newfile.write('name,email')
            newfile.close()
            f = open('students.csv').read()
        elif newcsv == 'n':
            sys.exit('Okay. Goodbye.')
    elif morecsv == 'n':
        sys.exit('Okay. Goodbye.')
students = {}
if f.split('\n') > 1:
    rows = f.split('\n')[1:]
    names = [j.split(',')[0] for j in rows]
    emails = [j.split(',')[1] for j in rows]
    for i in range(0,len(names)):
        students[names[i]] = emails[i]


def newstudent():
    newname = raw_input("What is the student's name? ")
    if newname == 'quit':
        return 'Okay! Nevermind.'
    if newname in students.keys():
        addnew = raw_input("%s is already in the list. Are you sure you want to add them again? y/n? " % newname)
        while addnew != 'y' and addnew!= 'n':
            addnew = raw_input("This is y/n only. %s is already in the list. Are you sure you want to add them again? y/n? " % newname)
        if addnew == 'y':
            newemail = raw_input("What is the student's email address? ")
            if newemail in students.values():
                email = students.keys()[students.values().index(newemail)]
                addnew = raw_input("%s is already used by another student, %s. Are you sure you want to add it to a new student? y/n? " % (newemail, email))
                while addnew != 'y' and addnew!= 'n':
                    addnew = raw_input("This is y/n only. %s is already in the list. Are you sure you want to add them again? y/n? " % newname)
                if addnew == 'y':
                    students[newname] = newemail
                if addnew == 'n':
                    return "Okay, let's try again."
            else:
                students[newname] = newemail
        elif addnew == 'n':
                return "Okay, let's try again."
    else:
        newemail = raw_input("What is the student's email address? ")       
        if newemail in students.values():
            email = students.keys()[students.values().index(newemail)]
            addnew = raw_input("%s is already used by another student, %s. Are you sure you want to add it to a new student? y/n? " % (newemail, email))
            while addnew != 'y' and addnew!= 'n':
                raw_input("This is y/n only. %s is already in the list. Are you sure you want to add them again? y/n? " % newname)
            if addnew == 'y':
                students[newname] = newemail
            elif addnew == 'n':
                return "Okay, let's try again."  
        students[newname] = newemail

def addstudent():
    newstudent()
    again = raw_input("Do you want to add another student? y/n? ")
    while again != 'y' and again != 'n':
        again = raw_input("The prompt was y/n only. Do you want to add another student? y/n? ")
    if again == 'y':
        addstudent()
    elif again == 'n':
        f = open('students.csv','w')
        f.truncate()
        f.write('name,email')
        for i in range(0,len(students.keys())):
            f.write('\n'+students.keys()[i]+','+students.values()[i])
        f.close()

addstudent()