can someone explain to me what I did wrong?

Question

I need help unscrambling this code. I am only allowed to use these specific lines of code, but I need to 'unscramble' it to make it work. To me, this code looks good but I don't seem to get it to work so I would like to find out why this is the case.

The assignment that I am trying to solve is as follows:

Read in the file using the csv reader and build a dictionary with the tree species as the key and a count of the number of times the tree appears. Use the "in" operator to see if a tree has been added, and if not set it to 1. Print the dictionary with the counts at the end.

My code is as follows:

from BrowserFile import open as _
import csv
with open("treeinventory.csv", "r", newline='') as f:
    count = {}
    reader = csv.reader(f)
    for yard in reader:
        for tree in yard:
            if tree in count:
                count[tree] = 1
            else: 
                count[tree] = count[tree] + 1
print(count)

I would love if someone can help me and also explain why this code is not able to work as it is, i am trying to learn and this would be very helpful!

thank you!

Answer 1

Generally, we don't solve "homework" problems on SO. You should also try to ask specific questions. Also put better titles on your questions. And, as such, I always like to post This to help new question askers out.

Since I'm here: The answer to your assignment is that line 9 and line 11 are swapped.

This is because the logic seems to set that dict count with the key tree is being set to 1 if the key is in the dict, and add 1 to the value stored at count[tree] if it's not in the dict. This will result in a KeyError exception to be thrown when the value is accessed to do this addition in the statement count[tree] + 1 , because, there is no value there yet.

Of course, without the input file, I can't actually run the code to verify it, so please try this out for yourself and update your question with specific issues if any come up.