Python - 打印不在列表中的项目

Question

I have a notepad that contains the following:

banana
apple

Additionally, I have a list. Say: example_list = ["banana", "apple", "orange"]

I want to print the values in example_list, that are not inside the notepad. So, desired outcome: orange

This is what I tried:

file = open("picturesLog.txt", "r")
fileLines = file.readlines()

example_list = ["banana", "apple", "orange"]

for item in example_list:
    if item in fileLines:
        pass
    else:
        print(item)

This is printing:

banana
apple
orange

Answer 1

Python reads the end-of-line character along with each line. You'll have to strip it off. Something like fileLines = [x.strip() for x in file.readlines()] should do the trick.

That would be the first change to make. It answers the original question.

The comments will be aflame with ways to improve the algorithm. Let them burn.

Answer 2

Or str.join :

l= set(map(str.rstrip,fileLines))
print('\n'.join([i for i in list if i not in l]))

Answer 3

>>> example_list = ["banana", "apple", "orange"]
>>> with open("picturesLog.txt") as f: 
...   seen = set(map(str.strip, f))
...   for fruit in set(example_list) - seen:
...     print(fruit)
... 
orange