Check if the very last element of a list matches a string of choice

Question

This sounds like it has been asked before but I cannot find anything that helps me.

My code is:

with open('file directory', 'r') as file:
data = []

for line in file:

    for word in line.split():
        data.append(str(word))
        last_word = str(data[-1])
        if last_word == "bobby":
            print("yes")
        else:print("no")

I want to know if the last element of the text file which I turned into a list matches a string, for example "bobby". Instead, what I get is basically a counter of how many times bobby was mentioned in the list.

Terminal:

yes
yes
yes

score 2 · Answer 1 · edited May 17 '21 at 17:54

2

How about:

with open('file directory', 'r') as file:
     last_line = f.readlines()[-1]
     print("yes" if last_line == "bobby" else "no")

or if you want to be short and cryptic:

with open('file directory', 'r') as file:
     print("yes" if f.readlines()[-1] == "bobby" else "no")

edited May 17 '21 at 17:54

Jab

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answered May 17 '21 at 17:47

Bernardo Trindade

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ternary operators don't work in python. use `print("yes" if f.readlines()[-1] == "bobby" else "no")` also this only checks if the last line is bobby not the last element – Jab May 17 '21 at 17:50
@Jab that's what happens when you answer a question during a meeting and your boss suddenly starts talking to you. Thanks. – Bernardo Trindade May 17 '21 at 17:52
lol it happens. although your edit is still not correct. – Jab May 17 '21 at 17:53
I fixed it for ya – Jab May 17 '21 at 17:54

score 1 · Answer 2 · edited May 17 '21 at 18:04

1

Instead of looping the file just turn it into a list and grab the last element. You're very close just the loop is unnecessary:

with open('file directory', 'r') as file:
    data = file.readlines()
    last_word = data[-1].split()[-1]
    if last_word == "bobby":
        print("yes")
    else:
        print("no")

edited May 17 '21 at 18:04

nullromo

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answered May 17 '21 at 17:46

Jab

26,853
21
75
114

Would I not need to split all the words and lines from the text file though? I only want to check the last word – Rrezon Beqiri May 17 '21 at 17:50
@RrezonBeqiri Thanks! fixed by adding split to the slice. should work – Jab May 17 '21 at 17:52
What is split supposed to be on the mapping line? – Rrezon Beqiri May 17 '21 at 17:56
I think the split function needs 2 arguments because I'm getting " split() missing 1 required positional argument: 'string'" as an error now – Rrezon Beqiri May 17 '21 at 18:00
1

It should be `data[-1].split()`, not `split(data[-1])`, but keep in mind you will still have an error if the last line is blank. – nullromo May 17 '21 at 18:02
Im not getting any errors but it also prints "no" when the last line is bobby and even though if i print last_word it literally says "['bobby']" – Rrezon Beqiri May 17 '21 at 18:06

score 1 · Accepted Answer · answered May 17 '21 at 17:48

1

If you want to look for the last word of each line, this works.

with open('asdf.txt', 'r') as file:
    for line in file:
        words = line.split()
        try:
            if words[-1] == "bobby":
                print("yes")
            else:
                print("no")
        except:
            # blank line
            pass

answered May 17 '21 at 17:48

nullromo

2,165
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1

This worked to check every single line perfectly! I only need the very last line but this was very helpful – Rrezon Beqiri May 17 '21 at 17:53
If you just want to look at the last line, you could use some of the code in the other answers. Keep in mind there are performance tradeoffs at play here. Take a look at this answer: https://stackoverflow.com/a/54278929/4476484 and note that reading the whole file with `readlines` would probably not be recommended for a very large file. Also, when using `file.readlines()[-1]`, you may run into an issue if the last line of the file is blank. Based on your application, you may want to ignore any potential last blank lines or you may not. Just something to be aware of. – nullromo May 17 '21 at 18:01

Check if the very last element of a list matches a string of choice

3 Answers3