Are there any libraries/toolkits that would help me in the task of extracting postal address information from unstructured PDF documents (e.g. letters)? If not, how would you approach this task?
I thought about using an open source PDF library and searching for the information with regex patterns, but I'm not sure if it's possible to reliably identify addresses with this simple approach. Unfortunately, the data mining course I attended didn't touch text mining, but only dealt with highly structured data. Maybe someone working on natural language processing knows a useful library or toolkit?
I would recommend http://pdfbox.apache.org for reading pdf(i.e converting to text) and http://code.google.com/p/graph-expression/ for writting Post address grammar.
Use pdf2xml or any other PDF library/toolkit and use your favorite search engine to search for "postal address extraction" and restrict your search to the filetype pdf.
Related
How I can generate random word from real language?
Anybody know any API from internet with this functional?
For example I send http-request to 'ht_tp://www.any...api.com/getword?lang=en' and I get responce 'Town'. Or 'Fast'. Or 'Received'... For example I send http-request to 'ht_tp://www.any...api.com/getword?lang=ru' and I get responce 'Ходить'. Or 'Шапка'. Or 'Отправлено'... Any form (noun, adjective, verb etc...) of the words of the any language.
I find resource 'http://www.randomlists.com/random-words'. But this is not JSON format, only English, and don't any warranty work in long time.
Please any ideas.
See this answer : https://stackoverflow.com/questions/824422/can-i-get-an-english-dictionary-word-list-somewhere Download a word dictionary, stick in the databse and fetch a random record or read a random line from the file each time. This way you don't depend on 3rd party API and you can extend it in all the languages you can find words for.
You can download the OpenOffice dictionaries. They come as extension (oxt), which is nothing different than a ZIP file. You may open them with 7zip or alike. Within you will find lots of files, interesting for you are the *.dic files. They will also contain resolutions or number words.
When you encounter something like abandon/LdS get rid of the /LdS this is used for hunspell.
Take these *.dic files use their name as key, put them into a database and pick a random word from there for a given language code.
Update
Older, but easier to access, the archived hunspell dictionaries from OpenOffice.
This question can be viewed in two ways and therefore I give two answers:
To collect words, I would run a spider on websites with known language (Wikipedia is a good starting point) and strip HTML tags.
To generate words from a real language is trickier. Using statistics from the collected words, it is possible to use Markow chains that produces statistically real words. I have tried letter by letter generation, and that works poorly. It is probably a better approach to use syllable construction instead.
I am working on a simple client-server project. Client is written in Java, it sends key words to C++ server written under Linux and recives a list of URLs with best ranks ( depending on number of occurrences of key words ). Server's job is to go through some URLs in search of key words and return best-fitting URLs. And now the problem is that I have to parse HTML sites to find occurrences of key words, plus I need to extract links from visited page to search on them as well. And my question is what library can I use to do that? Remember only C++ linux libraries are suitable for me. There were some similar topics, so I tried to go through most of them, but some of libraries parse only html files and I don't want to download every site I visit, but parse it on the fly and just store it's rank and url. Some of them look a bit complicated to me - for instance firstly parsing HTML to XML or something else and then finally work on the results with C++. Is there something simple and sufficient to do what I need it to do? Any advise will be appreciated.
I don't think regular expressions are appropriate for HTML parsing. I'm using libxml2, and I enjoy it very much - easy to use, portable and lightning fast.
To get URLs from the web using C/C++ you could use the libcurl library. To parse URLs and other not too easy stuff from the site you can use a regex library.
Separating the HTML tags from the real content can also be done without the use of a library.
For more advanced stuff one could use Qt which offers classes such as QWebPage (which uses WebKit) that allows one to access the DOM-Model of the page and extract individual HTML objects (e.g. single cells of a table) rather easyly.
You can try xerces-c. It's a powerful library for xml parsing. It support xml reading on the fly, dom and sax parsing.
(Not sure if this should be CW or not, you're welcome to comment if you think it should be).
At my workplace, we have many many different file formats for all kinds of purposes. Most, if not all, of these file formats are just written in plain text, with no consistency. I'm only a student working part-time, and I have no experience with using xml in production, but it seems to me that using xml would improve productivity, as we often need to parse, check and compare these outputs.
So my questions are: given that I can only control one small application and its output (only - the inputs are formats that are used in other applications as well), is it worth trying to change the output to be xml-based? If so, what are the best known ways to do that in C++ (i.e., xml parsers/writers, etc.)? Also, should I also provide a plain-text output to make it easy for the users (which are also programmers) to get used to xml? Should I provide a script to translate xml-plaintext? What are your experiences with this subject?
Thanks.
Don't just use XML because it's XML.
Use XML because:
other applications (that only accept XML) are going to read your output
you have an hierarchical data structure that lends itself perfectly for XML
you want to transform the data to other formats using XSL (e.g. to HTML)
EDIT:
A nice personal experience:
Customer: your application MUST be able to read XML.
Me: Er, OK, I will adapt my application so it can read XML.
Same customer (a few days later): your application MUST be able to read fixed width files, because we just realized our mainframe cannot generate XML.
Amir, to parse an XML you can use TinyXML which is incredibly easy to use and start with. Check its documentation for a quick brief, and read carefully the "what it does not do" clause. Been using it for reading and all I can say is that this tiny library does the job, very well.
As for writing - if your XML files aren't complex you might build them manually with a string object. "Aren't complex" for me means that you're only going to store text at most.
For more complex XML reading/writing you better check Xerces which is heavier than TinyXML. I haven't used it yet I've seen it in production and it does deliver it.
You can try using the boost::property_tree class.
http://www.boost.org/doc/libs/1_43_0/doc/html/property_tree.html
http://www.boost.org/doc/libs/1_43_0/doc/html/boost_propertytree/tutorial.html
http://www.boost.org/doc/libs/1_43_0/doc/html/boost_propertytree/parsers.html#boost_propertytree.parsers.xml_parser
It's pretty easy to use, but the page does warn that it doesn't support the XML format completely. If you do use this though, it gives you the freedom to easily use XML, INI, JSON, or INFO files without changing more than just the read_xml line.
If you want that ability though, you should avoid xml attributes. To use an attribute, you have to look at the key , which won't transfer between filetypes (although you can manually create your own subnodes).
Although using TinyXML is probably better. I've seen it used before in a couple of projects I've worked on, but don't have any experience with it.
Another approach to handling XML in your application is to use a data binding tool, such as CodeSynthesis XSD. Such a tool will generate C++ classes that hide all the gory details of parsing/serializing XML -- all that you see are objects corresponding to your XML vocabulary and functions that you can call to get/set the data, for example:
Person p = person ("person.xml");
cout << p.name ();
p.name ("John");
p.age (30);
ofstream ofs ("person.xml");
person (ofs, p);
Here's what previous SO threads have said on the topic. Please add others you know of that are relevant:
What is the best open XML parser for C++?
What is XML good for and when should i be using it?
What are good alternative data formats to XML?
BTW, before you decide on an XML parser, you may want to make sure that it will actually be able to parse all XML documents instead of just the "simple" ones, as discussed in this article:
Are you using a real XML parser?
I'm looking for a way if you know the location where to read the text for example say, under a particular category, how would you connect to a website and search & read the text from it?
what steps do i need to follow to learn about that?
you could use libcurl/cURL for your HTML retrival
You're probably looking for a web crawler.
Here's an example of a simple crawler written in C++.
Moreover, you might want to have a look to wget, a software to retrieve files via HTTP, HTTPS and FTP.
if you are looking at a specific web-page, you could try retrieving the page and parsing it to get to the exact location you want. e.g. specific div, etc.
since you are using c++, you could try reading up on using libcurl to retrieve the information you need from the URL.
You can download an html file with WinHTTP(working example) and then search the file. There's some find algos in the std::string class for searching if your needs are relatively basic.
How would I get a subset (say 100MB) of Wikipedia's pages? I've found you can get the whole dataset as XML but its more like 1 or 2 gigs; I don't need that much.
I want to experiment with implementing a map-reduce algorithm.
Having said that, if I could just find 100 megs worth of textual sample data from anywhere, that would also be good. E.g. the Stack Overflow database, if it's available, would possibly be a good size. I'm open to suggestions.
Edit: Any that aren't torrents? I can't get those at work.
The stackoverflow database is available for download.
Chris, you could just write a small program to hit the Wikipedia "Random Page" link until you get 100MB of web pages: http://en.wikipedia.org/wiki/Special:Random. You'll want to discard any duplicates you might get, and you might also want to limit the number of requests you make per minute (though some fraction of the articles will be served up by intermediate web caches, not Wikipedia servers). But it should be pretty easy.
One option is to download the entire Wikipedia dump, and then use only part of it. You can either decompress the entire thing and then use a simple script to split the file into smaller files (e.g. here), or if you are worried about disk space, you can write a something a script that decompresses and splits on the fly, and then you can stop the decompressing process at any stage you want. Wikipedia Dump Reader can by your inspiration for decompressing and processing on the fly, if you're comfortable with python (look at mparser.py).
If you don't want to download the entire thing, you're left with the option of scraping. The Export feature might be helpful for this, and the wikipediabot was also suggested in this context.
If you wanted to get a copy of the stackoverflow database, you could do that from the creative commons data dump.
Out of curiosity, what are you using all this data for?
You could use a web crawler and scrape 100MB of data?
There are a lot of wikipedia dumps available. Why do you want to choose the biggest (english wiki)? Wikinews archives are much smaller.
One smaller subset of Wikipedia articles comprises the 'meta' wiki articles. This is in the same XML format as the entire article dataset, but smaller (around 400MB as of March 2019), so it can be used for software validation (for example testing GenSim scripts).
https://dumps.wikimedia.org/metawiki/latest/
You want to look for any files with the -articles.xml.bz2 suffix.