Check for duplicates when printing

Question

I am generating serials using random and a base. (see example below)

import random

charList = ["A", "B", "C", "D", "C", "E", "F", "G", "H", "I", "J", "K", "L", "M",
"O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "1", "2", "3", "4", "5"
"6", "7", "8", "9"]

def Z150(charList):
    return "1841GG001Z" + random.choice(charList) + "8" + " -> Z150 Speakerset"
for i in range(100):
    print(Z150(charList))

Now, there's a very likely chance that there will be duplicates, how would I find the duplicates and remove them?

I have seen ways to do this but nothing that checks the outputs of the prints and then deletes the duplicates (if that makes sense)

Do you need to maintain order...trying to pick the right dupe — pault, Jun 10 '19 at 14:32
Possible duplicate of [Removing duplicates in Python lists](https://stackoverflow.com/questions/7961363/removing-duplicates-in-python-lists) or [How do you remove duplicates from a list whilst preserving order?](https://stackoverflow.com/questions/480214/how-do-you-remove-duplicates-from-a-list-whilst-preserving-order) — pault, Jun 10 '19 at 14:33

Green Cloak Guy · Answer 1 · 2019-06-10T14:37:12.850

1

One way using base python is to make a list of stuff you've already generated, and skip it:

printed = set()
for i in range(100):
    z150 = Z150(charList)
    if not z150 in printed:
        printed.add(z150)
        print(z150)

Or you can use a one-liner, and get a set in the first place, then print it afterwards:

snums = set(Z150(charList) for _ in range(100))
for s in snums: 
    print(s)

edited Jun 10 '19 at 14:37

answered Jun 10 '19 at 14:33

Green Cloak Guy

23,793
4
33
53

1

You don't need the check because `set` elements are always unique. Just do prints in a second loop. – meowgoesthedog Jun 10 '19 at 14:33
You do need the check, because you don't want to double-print it (assuming that `print()` is the main goal of this routine, and not "output to a data structure") – Green Cloak Guy Jun 10 '19 at 14:34
That's fair. Edited to present another solution accordingly – Green Cloak Guy Jun 10 '19 at 14:37

Smart Manoj · Accepted Answer · 2019-06-10T14:54:50.910

0

Use string module and shuffle

import random
import string

charList=list(string.ascii_uppercase+string.digits[1:])


def Z150(i):
    return  "1841GG001Z" + i + "8" + " -> Z150 Speakerset"
random.shuffle(charList)        
for i in charList[:20]:
    print(Z150(i))

edited Jun 10 '19 at 14:54

answered Jun 10 '19 at 14:35

Smart Manoj

5,230
4
34
59

Check for duplicates when printing

2 Answers2