比较两个.txt文件中的行，打印出不包含单词的新行

Question

I have the following piece of code that, for every line in textfile1, searches textfile2 and if the line is contained in textfile2 prints out the corresponding line of textfile2. I want to however, print out new line for every line not contained in textfile2. Here is the code:

def readline():
with open("textfile1.txt") as file, open("textfile2.txt") as file2:
    string = set(map(str.rstrip,file))
    for line in file2:
        spl = line.split(None, 1)[0]
        if spl in string:
            print(line.rstrip())    
        else:              ##if spl not in string print new line
            print("\n")

It doesn't work as I expect (doesn't print out any new lines), what may be the problem or any alternative solutions?

Sample Textfile1:

'
a
aa
ab
abandon
abandonaudiofocus
abandonsession
abort
abortablehttprequest
abortanimation
abortcaptures
abortconnection
abortpolicy
abortrequest
abs

Sample Textfile2:

'                |            22624
a                |               91
aa               |                7
ab               |                6
abort            |                8
abortanimation   |                5
abs              |              131
abslistview      |              115
absolutelayout   |               50
absolutesizespan |                6
abstracthttpentity |                2
abstractlist     |                1
abstractmap      |                4
abstractselector |                1
abstractset      |                2

Textfile1 includes many more words and it contains all the words in textfile2.

Answer 1

For every line in textfile2 , searches first part of it in textfile1 and if the line is contained in textfile2 prints out the corresponding line of textfile2 .

def readline():
        file1_list = [line.rstrip() for line in open("textfile1.txt")]
        file2_list = [line.rstrip() for line in open("textfile2.txt")]
        fileo_list = [line if line.split(None, 1)[0] in file1_list else '' for line in file2_list]
        for line in fileo_list:
            print(line)

This will print out:

'                |            22624
a                |               91
aa               |                7
ab               |                6
abort            |                8
abortanimation   |                5
abs              |              131


.....

Answer 2

According to your question -

for every line in textfile1, searches textfile2 and if the line is contained in textfile2 prints out the corresponding line of textfile2

And comment -

Textfile1 includes many more words and it contains all the words in textfile2

The logic you have right now if actually opposite, it checks for each line in file2 - textfile2.txt - whether that line's first part exists in the file - textfile1.txt - which would always be true, according to your comment.

You need to get all elements (first part of each line) of file2 in the set and then check each line of file . Example -

def get_first(line):
    return line.split(None, 1)[0]

def readline():
    with open("textfile1.txt",'r') as file, open("textfile2.txt",'r') as file2:
        string = set(map(get_first,file2))
        file2.seek(0)
        file2_dict = {}
        for line in file2:
            file2_dict[line.split(None, 1)[0]] = line
        for line in file:
            if line.strip() in string:
                print(file2_dict[line.rstrip()])    
            else:              ##if spl not in string print new line
                print()

Also, you do not need "\\n" inside your print() in else part, print also puts a newline by itself , you can just do - print() to print a newline.

---

Example/Demo -

>>> def get_first(line):
...     return line.split(None, 1)[0]
...
>>> def readline():
...     with open("a.txt",'r') as file, open("b.txt",'r') as file2:
...         string = set(map(get_first,file2))
...         for line in file:
...             if line.strip() in string:
...                 print(line.rstrip())
...             else:              ##if spl not in string print new line
...                 print()
...
>>> readline()
a
aa
ab



abort

abortanimation




abs

In the above example, a.txt contains data from your example textfile1.txt and b.txt contains data from example of textfile2.txt .

Answer 3

Sets make this pretty easy

with open("textfile1.txt") as file1:
    textfile_1_set = set(map(str.rstrip, file1))

with open("textfile2.txt") as file2:
    textfile_2_set = set([l.split()[0] for l in file2])

# remove all the lines that are in textfile2 from the 
# set of lines from textfile1
in_1_but_not_2 = textfile_1_set - textfile_2_set

for line in in_1_but_not_2:
    print line