# String exercises answers

# 1a ======================================================
def ToUpper(s):
    alpha_lower='abcdefghijklmnopqrstuvwxyz'
    alpha_upper='ABCDEFGHIJKLMNOPQRSTUVWXYZ'
    c=0
    answer=''
    while c < len(s):
        ch=s[c]
        pos=alpha_lower.find(ch)
        if pos >= 0:
            answer += alpha_upper[pos]
        else:
            answer += ch
        c += 1
    return answer

# 1b ==========================================================
Julius_before='defghijklmnopqrstuvwxyzabcDEFGHIJKLMNOPQRSTUVWXYZABC'
Julius_after ='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
def Encrypt(some_text):
    return Crypt(some_text, Julius_before, Julius_after)

def Decrypt(encrypted_text):
    return Crypt(encrypted_text, Julius_after, Julius_before)

def Crypt(the_text, alpha_from, alpha_to):
    c=0
    answer=''
    while c < len(the_text):
        ch=the_text[c]
        pos=alpha_from.find(ch)
        if pos >= 0:
            answer += alpha_to[pos]
        else:
            answer += ch
        c += 1
    return answer

# 2a ===========================================================
def IsSameName(name1,name2):
    return name1.upper() == name2.upper()

# 2b ===========================================================
def CapWord(word):
    return word[0].upper() + word[1:].lower()

# 2c ============================================================
def CapName(name):
    pos=name.find(' ')
    return CapWord(name[:pos+1]) + CapWord(name[pos+1:])

# 3a =============================================================
def FirstLast(name):
    pos=name.find(',')
    return name[pos+2:] + ' ' + name[:pos]

# 3b =============================================================
def FirstLastSequence(names):
    answer=''
    while names != '':
        pos = names.find(';')
        answer += FirstLast(names[:pos]) + ';'
        names = names[pos+1:]
    return answer

# 4 ==============================================================
def FileClassifier(filename):
    fname=filename.lower()
    if fname.endswith('.jpg') or fname.endswith('.jpeg'):
        return 'picture'
    if fname.endswith('.mp3'):
        return 'music'
    if fname.endswith('.nlogo'):
        return 'Netlogo'
    if fname.endswith('.py'):
        return 'Python'
    return 'Huh?'

# Triple Challenge ==================================================
alphabet='abcdefghijklmnopqrstuvwxyz'
crypt_text='Zw Z yrmv jvve wlikyvi zk zj sp jkreuzex fe kyv jyfcuvij fw Xzrekj.'
teams='JETS;NETS;KNICKS;GIANTS;RANGERS;YANKEES;METS;ISLANDERS;'

def Triple():
    shift=1
    alpha_from = alphabet + alphabet.upper()
    while shift < 26:
        alpha_to = ShiftAlpha(alphabet, shift)
        trial_text = Crypt(crypt_text, alpha_from, alpha_to)
        if CheckTeams(trial_text, teams):
            return trial_text
        shift += 1
    return 'Huh?'

def ShiftAlpha(s, shift_by):
    new_alpha = s[shift_by:] + s[:shift_by]
    return new_alpha + new_alpha.upper()

def CheckTeams(the_text, the_teams):
    THE_TEXT = the_text.upper()
    while the_teams != '':
        pos = the_teams.find(';')
        a_team = the_teams[:pos]
        if THE_TEXT.find(a_team) >= 0:
            return True
        the_teams = the_teams[pos+1:]
    return False