Password Generator

Code:
#!/usr/bin/python

#Password generater that uses type and length.

#There are 4 types to use: alphanum, alpha, alphacap, all

#d3hydr8[at]gmail[dot]com



import random, sys



def title():

    print "nt   d3hydr8[at]gmail[dot]com Password Gen v1.1"

    print "t-----------------------------------------------n"

    

def passgen(choice, length):

    

    passwd = ""

    

    alphanum = ('0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')

    alpha = ('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')

    alphacap = ('ABCDEFGHIJKLMNOPQRSTUVWXYZ')

    all = ('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_+=~`[]{}|:;"'<>,.?/')

    

    if str(choice).lower() == "alphanum":

        choice = alphanum



    elif str(choice).lower() == "alpha":

        choice = alpha

            

    elif str(choice).lower() == "alphacap":

        choice = alphacap

    

    elif str(choice).lower() == "all":

        choice = all

        

    else:

        print "Type doesn't matchn"

        sys.exit(1)

        

    return passwd.join(random.sample(choice, int(length)))

        

title()

if len(sys.argv) <= 3 or len(sys.argv) == 5:

    print "nUsage: ./passgen.py <type> <length of password> <how many>"

    print "t[options]"

    print "t   -w/-write <file> : Writes passwords to filen"

    print "There are 4 types to use: alphanum, alpha, alphacap, alln"

    sys.exit(1)



for arg in sys.argv[1:]:

    if arg.lower() == "-w" or arg.lower() == "-write":

        txt = sys.argv[int(sys.argv[1:].index(arg))+2]



if sys.argv[3].isdigit() == False:

    print sys.argv[3],"must be a numbern"

    sys.exit(1)

if sys.argv[2].isdigit() == False:

    print sys.argv[2],"must be a numbern"

    sys.exit(1)

try:

    if txt:

        print "[+] Writing Data:",txt

        output = open(txt, "a")

except(NameError):

    txt = None

    pass



for x in xrange(int(sys.argv[3])):

    if txt != None:

        output.writelines(passgen(sys.argv[1],sys.argv[2])+"n")

    else:

        print "Password:",passgen(sys.argv[1],sys.argv[2])

print "n[-] Donen"