如何用 Python 中包含相同数据的单行文本替换文件中的多个 3 行文本块

Question

I have a text file containing multiple 3 line blocks of text followed by a single new line. My data looks like this:

title A - description
http://www.a.site.com/
http://a.anothersite.com/

title B - blah blah
http://www.site.b.com/
http://b.anothersite.com/

title C - yeah yeah
http://www.site.c.com/
http://anothersite.c.com/

The output I'm hoping to achieve is something like this:

title A - description | http://www.a.site.com/ | http://a.anothersite.com/   
title B - blah blah | http://www.site.b.com/ | http://b.anothersite.com/
title C - yeah yeah | http://www.site.c.com/ | http://anothersite.c.com/

I've been trying to do this with python and I'm not really getting anywhere. The best I was able to accomplish was removing all new lines but that doesn't really help in this case as I still need a new line between each piece of data. Any suggestions?

Answer 1

three_lines_joined = ''
strings_to_join = []
results = []


for index, item in enumerate(text):
    if item is not '\n':
        strings_to_join.append(item.strip())
    else:
        three_lines_joined = ' | '.join(strings_to_join)
        results.append(three_lines_joined)
        three_lines_joined = ''
        strings_to_join = []

Answer 2

Here is my solution using regular expressions and replace

import re

text = """
title A - description
http://www.a.site.com/
http://a.anothersite.com/

title B - blah blah
http://www.site.b.com/
http://b.anothersite.com/

title C - yeah yeah
http://www.site.c.com/
http://anothersite.c.com/
"""

text = text.strip()
text = re.sub('[^\n](\n)[^\n]', ' | ', text).replace('\n\n', '\n')

print(text)

Answer 3

Try this:

import re
with open("file.txt", "r+") as f:
    text = " | ".join(f.readlines())
    text = re.sub(r"(?<!^)\n", '', text)
    text = re.sub(r"\s*\|\s*\|\s*", "\n", text)

    f.seek(0)
    f.write(text)

Output of file.txt :

title A - description | http://www.a.site.com/ | http://a.anothersite.com/
title B - blah blah | http://www.site.b.com/ | http://b.anothersite.com/
title C - yeah yeah | http://www.site.c.com/ | http://anothersite.c.com/

Answer 4

First remove empty lines as you did, then use lines = fulltext.split("\\n") to get a list of lines. Then run something like this:

for i in range(len(lines))/3:
    title, desc = lines[3*a].split("-")
    website1, website2 = lines[3*a+1], lines[3*a+2]
    print(title + " - " + desc + " | " + website1 + " - " + website2)

which allows you to also use the variables in your code. If you really just want a text output then looking at your input try:

fulltext.replace("\n"," ")

which should produce your desired text output (maybe with a little modification). However, I'd reccomend the first version more as it would allow you to later for example use those values for something else. Variales are generally more useful then formatted text documents.