import string
import random
 
#alphabet mask
mask_all    = 0x0      #String of characters which are considered printable.
                       #This is a combination of all masks values
mask_abc    = 0x1      #The lowercase letters 'abcdefghijklmnopqrstuvwxyz'
mask_ABC    = 0x2      #The uppercase letters 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
mask_123    = 0x4      #The string '0123456789'
mask_white  = 0x8      #A string containing all characters that are considered
                       #whitespace. On most systems this includes the characters
                       #space, tab, linefeed, return, formfeed, and vertical
                       #tab.
mask_punct  = 0x10     #String of ASCII characters which are considered
                       #punctuation characters in the C locale.
 
def generator (alphamask, size):
    if (alphamask > 0x1F) or (alphamask < 0):
        alphamask = alphamask and 0x1F
    alfa = ''
    if alphamask == 0:
        alfa = string.printable
    else:
        if alphamask & mask_abc:
            alfa += string.lowercase
        if alphamask & mask_ABC:
            alfa += string.uppercase
        if alphamask & mask_123:
            alfa += string.digits
        if alphamask & mask_white:
            alfa += string.whitespace
        if alphamask & mask_punct:
            alfa += string.punctuation
    if size > 0:
        ret = ''
        for i in range (0, size):
            ret += random.choice(alfa)
        return ret
    else:
        print 'size should be positive integer'
        return ''
 
def main():
    #ejemplos
    print generator(1, 10)
    print generator(2, 20)
    print generator(4, 30)
    print generator(8, 40)
    print generator(16, 50)
    print generator(7, 50)
 
if __name__ == '__main__':
    main()