Use endswith() to check if a string in one list ends with a string from another list?

Question

I need to check if items within a list is listed at the end of a string in another list, preferably by using endswith() somehow but I'm not really sure how to solve it with just this method and not let it depend on length of the other list etc..

For a single list this works perfectly fine:

mylist = ["item 1 a", "item 2 a", "item 3 b"]

for item in mylist:
    if item.endswith("a"):
        print(f"{item} ends with 'a'")
    else:
        print(f"{item} ends with 'b'")

# Output: 
# item 1 a ends with 'a'
# item 2 a ends with 'a'
# item 3 b ends with 'b'

But let's say I have 2 lists instead, I'm not sure how to check if a listitem in one list ends with one of the options from another list. Since endswith() just returns True or False, I'm fully aware of the code below being wrong, but it's more a way of showing how I want it to work:

mylist = ["item 1", "item 2", "item 3"]
newlist = ["added item 1", "added item 3"]

for item in mylist:
    if item.endswith(item) in newlist:
# Wont work because the return is a boolean
# value, just an example of what I'm looking for'
        print(f"newlist has {item} added")
    else:
        print(f"newlist still waiting for {item}")

I know there are other ways to get the same result but is there any way to do this without the need for using regular expressions or yet another list to store the different strings to and just base it on endswith()?

You're only checking if strings end in `a`, are you saying you'd like to check if a string ends in any string from a list of strings? — Grismar, May 31 '22 at 07:01
I corrected my examplecode, i meant to check for each string in the first list to be the end of strings in the second list. Sorry for the confusion — NinjaSnickers, May 31 '22 at 07:04

Albert Rial · Answer 1 · 2022-05-31T07:24:00.773

1

Your example code is a bit confusing but if you want to check which items in mylist are a suffix of any string inside newlist the following should work:

mylist = ["item 1", "item 2", "item 3"]
newlist = ["added item 1", "added item 3"]

for item in mylist:
    found = False
    
    for newitem in newlist:
       if newitem.endswith(item):
           found = True
           break

    if found:
       print(f"newlist has {item} added")
    else:
       print(f"newlist still waiting for {item}")

The output of this code is the following, which I guess is what you wanted:

newlist has item 1 added
newlist still waiting for item 2
newlist has item 3 added

edited May 31 '22 at 07:24

answered May 31 '22 at 07:09

Albert Rial

106
7

1

the if statement needs to be 'if newitem .endswith(item):' intend of 'if newlist.endswith(item):' – Ohad Sharet May 31 '22 at 07:14
1

Yes, my bad. I just discovered it while running the code and corrected it. Thank you! – Albert Rial May 31 '22 at 07:17

score 1 · Accepted Answer · answered May 31 '22 at 07:11

If I understood you correctly this should be the solution

mylist = ["item 1", "item 2", "item 3"]
newlist = ["added item 1", "added item 3"]

for item in mylist:
    for other_item in newlist:
        if other_item.endswith(item):
            print(f"newlist has {item} added")
            break
        
        print(f"newlist still waiting for {item}")

Console output is this

newlist has item 1 added
newlist still waiting for item 2
newlist still waiting for item 2
newlist still waiting for item 3
newlist has item 3 added

If you don't want the output for item 2 to be duplicate you can just add a variable where you store if the second for loop found the item and if not you can write that message. Something like:

mylist = ["item 1", "item 2", "item 3"]
newlist = ["added item 1", "added item 3"]

for item in mylist:
    found = False
    for other_item in newlist:
        if other_item.endswith(item):
            print(f"newlist has {item} added")
            found = True
            break

    if found is not True:
        print(f"newlist still waiting for {item}")

Which gets you just:

newlist has item 1 added
newlist still waiting for item 2
newlist has item 3 added

score 0 · Answer 3 · answered May 31 '22 at 07:11

It looks like you just need nested loops to check each item in list 1 with every item in list 2.

mylist = ["item 1", "item 2", "item 3"]
newlist = ["added item 1", "added item 3"]

for item in newlist:
  for item1 in mylist:
    if item1.endswith(item):
        print(f"newlist has {item} added")
    else:
        print(f"newlist still waiting for {item}")

Use endswith() to check if a string in one list ends with a string from another list?

3 Answers3