Gene Probability Python Code, with spreadsheet creator

import random
import xlwt
import sys

## {{{ http://code.activestate.com/recipes/577058/ (r2)
def query_yes_no(question, default="yes"):
    """Ask a yes/no question via raw_input() and return their answer.

    "question" is a string that is presented to the user.
    "default" is the presumed answer if the user just hits <Enter>.
        It must be "yes" (the default), "no" or None (meaning
        an answer is required of the user).

    The "answer" return value is one of "yes" or "no".
    """
    valid = {"yes":"yes",   "y":"yes",  "ye":"yes",
             "no":"no",     "n":"no"}
    if default == None:
        prompt = " [y/n] "
    elif default == "yes":
        prompt = " [Y/n] "
    elif default == "no":
        prompt = " [y/N] "
    else:
        raise ValueError("invalid default answer: '%s'" % default)

    while 1:
        sys.stdout.write(question + prompt)
        choice = raw_input().lower()
        if default is not None and choice == '':
            return default
        elif choice in valid.keys():
            return valid[choice]
        else:
            sys.stdout.write("Please respond with 'yes' or 'no' "\
                             "(or 'y' or 'n').\n")
## end of http://code.activestate.com/recipes/577058/ }}}


genotype = [0,0]
homoDom=0;
heteroDom=0;
homoRec=0;
dom=0;
rec=0;
bigtable=[]
print "Genotype\t| Genotype name\t\t| Phenotype"
print "====================================================="
for x in range(0,100):
    genotype[0]=int(random.randrange(0,100)/50)
    genotype[1]=int(random.randrange(0,100)/50)
    if genotype[0] == 1:
            if genotype[1] == 1:
                print "RR \t\t| homozygous dominant\t| normal skin"
                bigtable.append(["RR", "homozygous dominant", "normal skin"])
                homoDom+=1
            else:
                print "Rr \t\t| heterozygous dominant\t| normal skin"
                bigtable.append(["Rr", "heterozygous dominant", "normal skin"])
                heteroDom+=1
    else:
        if genotype[1] == 1:
            print "rR\t\t| heterozygous dominant\t| normal skin"
            bigtable.append(["rR", "heterozygous dominant", "normal skin"])
            heteroDom+=1
        else:
            print "rr\t\t| homozygous recessive\t| albino"
            bigtable.append(["rr", "homozygous recessive", "normal skin"])
            homoRec+=1
print "Statistics:"
print "RR: "+str(homoDom)+"/100 Rr or rR: "+str(heteroDom)+"/100 rr: "+str(homoRec)+"/100."
rec=homoRec
dom=homoDom+heteroDom
print str(dom)+"/100 were dominant. "+str(rec)+"/100 were recessive."
print "Look over the results above. \n"
resp=query_yes_no("Create an Excel worksheet? Press ENTER or y to create one, otherwise n to simply exit.")
if resp == 'yes':
    print "============================================================="
    print "Creating Excel worksheet..."
    print "============================================================="
    wbk = xlwt.Workbook()
    sheet = wbk.add_sheet('Trait Lab Results')

    # Create a bold font to use
    boldstyle = xlwt.XFStyle()

    # Create a font to use with the style
    font = xlwt.Font()
    font.bold = True

    # Set the style's font to this new one you set up
    boldstyle.font = font

    # Create the header!
    # Starts at zero, goes by row,column
    sheet.write(0,0,'Genotype',boldstyle)
    sheet.write(0,1,'Genotype Name',boldstyle)
    sheet.write(0,2,'Phenotype',boldstyle)

    rowi=1
    # Import the data!
    for result in bigtable:
        sheet.write(rowi, 0, result[0])
        sheet.write(rowi, 1, result[1])
        sheet.write(rowi, 2, result[2])
        rowi+=1
    try:
        wbk.save('TraitLabGenotypesPhenotypesResults.xls')
        print "Done! The Excel spreadsheet is called TraitLabGenotypesPhenotypesResults.xls."
    except IOError:
        print "Error: Excel spreadsheet couldn't be created! :("