Python Forum

So I understand that there are better ways of doing this. I figuered out a couple ways but I am still perplexed as to why this didn't work. I am getting an "IndexError: list index out of range" but I can't figure out why.

Input:

guest_list = ['Guest 1', 'Guest 2', 'Guest 3', 'Guest 4', "Guest 5"]

guest_list_len = (len(guest_list))

x=0

while x <= guest_list_len:
    print (guest_list[x] + ", you are invited to a party!")
    print (str(x), len(guest_list))
    x += 1

Output:

Output:
Traceback (most recent call last):
Guest 1, you are invited to a party!
0 5
  File "C:/Users/xxxxxxx/PycharmProjects/lists/guest_list.py", line 10, in <module>
Guest 2, you are invited to a party!
    print (guest_list[x] + ", you are invited to a party!")
1 5
IndexError: list index out of range
Guest 3, you are invited to a party!
2 5
Guest 4, you are invited to a party!
3 5
Guest 5, you are invited to a party!
4 5

Process finished with exit code 1

As you can see, none of my list indexs are out of range. Thanks for your help!

-Josh

---

Yay! I figured it out all by myself! The loop should not have been >= because the last element in the list will be numbered one less than the actual count of elements.
The corect loop is while x < guest_list_len:

(May-18-2019, 03:23 PM)rogueakula Wrote: [ -> ]So I understand that there are better ways of doing this.

Yes,for loop with enumerate() would be better,and more Pythonic.

guest_list = ['Guest 1', 'Guest 2', 'Guest 3', 'Guest 4', "Guest 5"]
for index,guest in enumerate(guest_list):
    print (f"{guest}, you are invited to a party!")
    print(index, len(guest_list))

Same output as your code.
More sense to also take people out of list,over it just print len() of gust_list 5 time.

guest_list = ['Guest 1', 'Guest 2', 'Guest 3', 'Guest 4', "Guest 5"]
for people_count,guest in enumerate(guest_list, 1):
    print('-'*15)
    print (f"{guest}, you are invited to a party!")
    print(f"{people_count} guest at party now,{len(guest_list)-people_count} guest now remain in guest_list")

Output:
Guest 1, you are invited to a party!
1 guest at party now,4 guest now remain in guest_list
---------------
Guest 2, you are invited to a party!
2 guest at party now,3 guest now remain in guest_list
---------------
Guest 3, you are invited to a party!
3 guest at party now,2 guest now remain in guest_list
---------------
Guest 4, you are invited to a party!
4 guest at party now,1 guest now remain in guest_list
---------------
Guest 5, you are invited to a party!
5 guest at party now,0 guest now remain in guest_list