# String-List-File Exercises

# --------------------------------- Problem #1 ---------------
def wc(filename):
    try:
        f=open(filename,'rU')
        s=f.read()
    except:
        return [0,0,0]
    chars=len(s)
    words=len(s.split())
    lines=len(s.split('\n'))
    return [chars,words,lines]

# ---------------------- Problem #2: ------------------------
#   there are two helper functions 

def firstVowelPos(s):
    vowels='aeiouAEIOU'
    for i in range(len(s)):
        if s[i] in vowels:
            return i
    return -1

def pigify(word):
    letters='abcdefghijklmnopqrstuvwxyz'
    # remove and store trailing punctuation, if it exists
    if word[-1] in letters:
        p=''
    else:
        p=word[-1]
        word=word[:-1]
    pos=firstVowelPos(word)
    if pos>0:
        word=word[pos:]+word[:pos]+'ay'
    else:
        word+='way'
    # put the punctuation back
    word+=p
    return word
    
def igpay(infile,outfile):

    #read the file
    try:
        f=open(infile,'rU')
        s=f.read()
    except:
        return  # there should be a better way to indicate that we failed
    outlines=[]
    # split it into lines
    inlines=s.split('\n')
    for line in inlines:
        # split each line into a list of words
        words=line.split()
        outwords=[]
        for word in words:
            pigword=pigify(word)
            outwords.append(pigword)
        # create a line (string) from the pigified words
        outlines.append(' '.join(outwords))
    # join the lines together...
    outs='\n'.join(outlines)
    # write it out
    try:
        f=open(outfile,'w')
        f.write(outs)
        f.close()
    except:
        pass
    return

# ----------------------------- Problem #3 --------------------------
def HighLow(filename):
    try:
        f=open(filename,'rU')
        lines=f.read().split('\n')
        f.close()
    except:
        print 'Problem with opening: '+filename
        return
    if len(lines)==0:
        print 'no data in file'
        return
    
    # ignore the first line of column headers, and set up the first
    #  versions of the answer variables:
    words=lines[1].split(',')
    highname,highgrade=words[0],int(words[1])
    lowname,lowgrade=highname,highgrade
    
    # now, go through the rest of the lines:
    for i in range(2,len(lines)):
        words=lines[i].split(',')
        if len(words)==2:   # ignore any lines without 2 words
            name,grade=words[0],int(words[1])
            if grade>highgrade:
                highname,highgrade=name,grade
            elif grade<lowgrade:
                lowname,lowgrade=name,grade

    # Done, now print:
    print 'highest: %s with %d' % (highname,highgrade)
    print 'lowest: %s with %d' % (lowname,lowgrade)

# --------------------------- Problem #4 ---------------------------
def Rank(infile,outfile):
    try:
        f=open(infile,'rU')
        lines=f.read().split('\n')
        f.close()
    except:
        return      # there should be a better way of indicating failure than this
    listOfLists=[]
    for i in range(1,len(lines)):
        words=lines[i].split(',')
        if len(words)==2:
            miniList=[int(words[1]),words[0]]
            listOfLists.append(miniList)
    listOfLists.sort(reverse=True)
    # Done, write it out
    try:
        f=open(outfile,'w')
    except:
        return
    f.write('Name,Grade\n')
    for mini in listOfLists:
        f.write(mini[1]+','+str(mini[0])+'\n')
    f.close()
         

# ---------------------------- Problem #5: ----------------------------
def CharRank(filename):
    f=open(filename,'rU')
    s=f.read().lower()
    f.close()

    alpha='abcdefghijklmnopqrstuvwxyz'
    # let's count the occurrence of each letter in a separate list of the same length, pre-filled with zeros
    counts=[0]*26
    for c in s:
        pos=alpha.find(c)
        if pos>=0:
            counts[pos]+=1
    # now we know that, for instance, the 4th letter (which is 'd', or alpha[3])
    #   has occurred counts[3] times in the text

    # Next step: create a list of elements that look like: [counts[0],'a'], [counts[1],'b'], ... etc.
    pairs=[]
    for i in range(len(alpha)):
        pairs.append([counts[i],alpha[i]])

    # sort it, from smallest to largest
    pairs.sort()
    pairs=pairs[::-1]  # reverse the list
    
    # re-create the alphabet in decreasing rank order
    new_alpha=''
    for apair in pairs:
        if apair[0]>0:  # include the letter only if it actually occurred in the text
            new_alpha+=apair[1]

    return new_alpha