Python Regex - Extract text between (multiple) expressions in a textfile - python

I am a Python beginner and would be very thankful if you could help me with my text extraction problem.
I want to extract all text, which lies between two expressions in a textfile (the beginning and end of a letter). For both, the beginning and the end of the letter there are multiple possible expressions (defined in the lists "letter_begin" and "letter_end", e.g. "Dear", "to our", etc.). I want to analyze this for a bunch of files, find below an example of how such a textfile looks like -> I want to extract all text starting from "Dear" till "Douglas". In cases where the "letter_end" has no match, i.e. no letter_end expression is found, the output should start from the letter_beginning and end at the very end of the text file to be analyzed.
Edit: the end of "the recorded text" has to be after the match of "letter_end" and before the first line with 20 characters or more (as is the case for "Random text here as well" -> len=24.
"""Some random text here
 
Dear Shareholders We
are pleased to provide you with this semiannual report for Fund for the six-month period ended April 30, 2018. For additional information about the Fund, please visit our website a, where you can access quarterly commentaries. We value the trust that you place in us and look forward to serving your investment needs in the years to come.
Best regards
Douglas
Random text here as well"""
This is my code so far - but it is not able to flexible catch the text between the expressions (there can be anything (lines, text, numbers, signs, etc.) before the "letter_begin" and after the "letter_end")
import re
letter_begin = ["dear", "to our", "estimated"] # All expressions for "beginning" of letter
openings = "|".join(letter_begin)
letter_end = ["sincerely", "yours", "best regards"] # All expressions for "ending" of Letter
closings = "|".join(letter_end)
regex = r"(?:" + openings + r")\s+.*?" + r"(?:" + closings + r"),\n\S+"
with open(filename, 'r', encoding="utf-8") as infile:
text = infile.read()
text = str(text)
output = re.findall(regex, text, re.MULTILINE|re.DOTALL|re.IGNORECASE) # record all text between Regex (Beginning and End Expressions)
print (output)
I am very thankful for every help!

You may use
regex = r"(?:{})[\s\S]*?(?:{}).*(?:\n.*){{0,2}}".format(openings, closings)
This pattern will result in a regex like
(?:dear|to our|estimated)[\s\S]*?(?:sincerely|yours|best regards).*(?:\n.*){0,2}
See the regex demo. Note you should not use re.DOTALL with this pattern, and the re.MULTILINE option is also redundant.
Details
(?:dear|to our|estimated) - any of the three values
[\s\S]*? - any 0+ chars, as few as possible
(?:sincerely|yours|best regards) - any of the three values
.* - any 0+ chars other than newline
(?:\n.*){0,2} - zero, one or two repetitions of a newline followed with any 0+ chars other than newline.
Python demo code:
import re
text="""Some random text here
Dear Shareholders We
are pleased to provide you with this semiannual report for Fund for the six-month period ended April 30, 2018. For additional information about the Fund, please visit our website a, where you can access quarterly commentaries. We value the trust that you place in us and look forward to serving your investment needs in the years to come.
Best regards
Douglas
Random text here as well"""
letter_begin = ["dear", "to our", "estimated"] # All expressions for "beginning" of letter
openings = "|".join(letter_begin)
letter_end = ["sincerely", "yours", "best regards"] # All expressions for "ending" of Letter
closings = "|".join(letter_end)
regex = r"(?:{})[\s\S]*?(?:{}).*(?:\n.*){{0,2}}".format(openings, closings)
print(regex)
print(re.findall(regex, text, re.IGNORECASE))
Output:
['Dear Shareholders We\nare pleased to provide you with this semiannual report for Fund for the six-month period ended April 30, 2018. For additional information about the Fund, please visit our website a, where you can access quarterly commentaries. We value the trust that you place in us and look forward to serving your investment needs in the years to come.\nBest regards \nDouglas\n']

Related

Why doesn't this pattern with a negative look-ahead restrict these overrides of the re.sub() function?

Using a negative look-ahead X(?!Y), check that it is NOT ahead of the match, the goal is to identify substrings "they" that are not ahead some sequence ((PERS)the , and if there aren't any then than replace that substring "they" with the string "((PERS)they NO DATA) ". Otherwise you should not make any replacement.
import re
# Example 1 :
input_text = "They are great friends, the cellos of they, soon they became best friends. They saw each other in the park before taking the old cabinets, since ((PERS)the printers) were still useful to the company themselves. They are somewhat worse than the new models."
# Example 2 :
input_text = "They finished the flow chart pretty quickly"
input_text = re.sub(r"\(\(PERS\)\s*the", "((PERS)the", input_text)
#constraint_pattern = r"\bthey\b(?<!\(\(PERS\)/s*the)" # --> re.error: look-ahead requires fixed-width pattern
constraint_pattern = r"\bellos\b(?<!\(\(PERS\)the)"
input_text = re.sub(constraint_pattern,
"((PERS)they NO DATA)",
input_text, flags = re.IGNORECASE)
print(input_text) # --> output
Using this code, for some reason all occurrences of the "ellos" substring are replaced by "((PERS)they NO DATA)", but really only "they" substrings that are NOT preceded by a sequence "((PERS)the" must be replaced by "((PERS)they NO DATA)"
The goal is really to get this output:
#correct output for example 1
"((PERS)they NO DATA) are great friends, the cellos of ((PERS)they NO DATA), soon ((PERS)they NO DATA) became best friends. ((PERS)they NO DATA) saw each other in the park before taking the old cabinets, since ((PERS)the printers) were still useful to the company themselves. They are somewhat worse than the new models."
#correct output for example 2
"((PERS)they NO DATA) finished the flow chart pretty quickly"

How do I extract the entire sentence from a job description which consists the number of years of experience in it?

I've been working on a job description parser and I have been trying to extract the entire sentence which consists of the number of years of experience required.
I have tried to use regex which provides me the number of years but not the entire sentence.
def extract_years(self,resume_text):
resume_text = str(resume_text.split('.'))
exp=[]
rx = re.compile(r"(\d+(?:-\d+)?\+?)\s*(years?)",re.I)
for word in resume_text:
exp_temp = rx.search(resume_text)
if exp_temp:
exp.append(exp_temp[0])
exp = list(set(exp))
return exp
Output:
['5-7 years']
Desired Output:
['5-7 years of experience in journalism, communications, or content creation preferred']
Try: (\d+(?:-\d+)?+?)\s*(years?).*
Though I'm somewhat new to Regex, I believe you can get what you desire using a combination of ".*" to end of your match terms and possibly the beginning if "5-7 years" comes after some characters like "needs 5-7 years of experience".
just adding the group ".*" at the end would mean to add any combination of characters, 0 or more after your initial match stopping at a line break, to match the entire sentence.
Hope this helps.

Regex not specific enough

So I wrote a program for my Kindle e-reader that searches my highlights and deletes repetitive text (it's usually information about the book title, author, page number, etc.). I thought it was functional but sometimes there would random be periods (.) on certain lines of the output. At first I thought the program was just buggy but then I realized that the regex I'm using to match the books title and author was also matching any sentence that ended in brackets.
This is the code for the regex that I'm using to detect the books title and author
titleRegex = re.compile('(.+)\((.+)\)')
Example
Desired book title and author match: Book title (Author name)
What would also get matched: *I like apples because they are green (they are sometimes red as well). *
In this case it would delete everything and leave just the period at the end of the sentence. This is obviously not ideal because it deletes the text I highlighted
Here is the unformatted text file that goes into my program
The program works by finding all of the matches for the regexes I wrote, looping through those matches and one by one replacing them with empty strings.
Would there be any ways to make my title regex more specific so that it only picks up author titles and not full sentences that end in brackets? If not, what steps would I have to take to restructure this program?
I've attached my code to the bottom of this post. I would greatly appreciate any help as I'm a total coding newbie. Thanks :)
import re
titleRegex = re.compile('(.+)\((.+)\)')
titleRegex2 = re.compile(r'\ufeff (.+)\((.+)\)')
infoRegex = re.compile(r'(.) ([a-zA-Z]+) (Highlight|Bookmark|Note) ([a-zA-Z]+) ([a-zA-Z]+) ([0-9]+) (\|)')
locationRegex = re.compile(r' Location (\d+)(-\d+)? (\|)')
dateRegex = re.compile(r'([a-zA-Z]+) ([a-zA-Z]+) ([a-zA-Z]+), ([a-zA-Z]+) ([0-9]+), ([0-9]+)')
timeRegex = re.compile(r'([0-9]+):([0-9]+):([0-9]+) (AM|PM)')
newlineRegex = re.compile(r'\n')
sepRegex = re.compile('==========')
regexList = [titleRegex, titleRegex2, infoRegex, locationRegex, dateRegex, timeRegex, sepRegex, newlineRegex]
string = open("/Users/devinnagami/myclippings.txt").read()
for x in range(len(regexList)):
newString = re.sub(regexList[x], ' ', string)
string = newString
finalText = newString.split(' ')
with open('booknotes.txt', 'w') as f:
for item in finalText:
f.write('%s\n' % item)
There isn't enough information to tell if "Book title (Book Author)" is different than something like "I like Books (Good Ones)" without context. Thankfully, the text you showed has plenty of context. Instead of creating several different regular expressions, you can combine them into one expression to encode that context.
For instance:
quoteInfoRegex = re.compile(
r"^=+\n(?P<title>.*?) \((?P<author>.*?)\)\n" +
r"- Your Highlight on page (?P<page>[\d]+) \| Location (?P<location>[\d-]+) \| Added on (?P<added>.*?)\n" +
r"\n" +
r"(?P<quote>.*?)\n", flags=re.MULTILINE)
for m in quoteInfoRegex.finditer(data):
print(m.groupdict())
This will pull out each line of the text, and parse it, knowing that the book title is the first line after the equals, and the quote itself is below that.

Python regex to find phrases contain exact words

I have a list of strings and wish to find exact phases.
So far my code finds the month and year only, but the whole phase including “- Recorded” is needed, like “March 2016 - Recorded”.
How can it add on the “- Recorded” to the regex?
import re
texts = [
"Shawn Dookhit took annual leave in March 2016 - Recorded The report",
"Soondren Armon took medical leave in February 2017 - Recorded It was in",
"David Padachi took annual leave in May 2016 - Recorded It says",
"Jack Jagoo",
"Devendradutt Ramgolam took medical leave in August 2016 - Recorded Day back",
"Kate Dudhee",
"Vinaye Ramjuttun took annual leave in - Recorded Answering"
]
regex = re.compile('(?P<month>[a-zA-Z]+)\s+(?P<year>\d{4})\s')
for t in texts:
try:
m = regex.search(t)
print m.group()
except:
print "keyword's not found"
You got 2 named groups here: month and year which takes month and year from your strings. To get - Recorded into recorded named group you can do this:
regex = re.compile('(?P<month>[a-zA-Z]+)\s+(?P<year>\d{4})\s(?P<recorded>- Recorded)')
Or if you can just add - Recorded to your regex without named group:
regex = re.compile('(?P<month>[a-zA-Z]+)\s+(?P<year>\d{4})\s- Recorded')
Or you can add named group other with hyphen and one capitalized word:
regex = re.compile('(?P<month>[a-zA-Z]+)\s+(?P<year>\d{4})\s(?P<other>- [A-Z][a-z]+)')
I think first or third option is preferable because you already got named groups. Also i recommend you to use this web site http://pythex.org/, it really helps to construct regex :).
Use a list comprehension with the corrected regex:
regex = re.compile('(?P<month>[a-zA-Z]+)\s+(?P<year>\d{4})\s* - Recorded')
matches = [match.groups() for text in texts for match in [regex.search(text)] if match]
print(matches)
# [('March', '2016'), ('February', '2017'), ('May', '2016'), ('August', '2016')]

Python - RegEx for splitting text into sentences (sentence-tokenizing) [duplicate]

This question already has answers here:
How can I split a text into sentences?
(20 answers)
Closed 3 years ago.
I want to make a list of sentences from a string and then print them out. I don't want to use NLTK to do this. So it needs to split on a period at the end of the sentence and not at decimals or abbreviations or title of a name or if the sentence has a .com This is attempt at regex that doesn't work.
import re
text = """\
Mr. Smith bought cheapsite.com for 1.5 million dollars, i.e. he paid a lot for it. Did he mind? Adam Jones Jr. thinks he didn't. In any case, this isn't true... Well, with a probability of .9 it isn't.
"""
sentences = re.split(r' *[\.\?!][\'"\)\]]* *', text)
for stuff in sentences:
print(stuff)
Example output of what it should look like
Mr. Smith bought cheapsite.com for 1.5 million dollars, i.e. he paid a lot for it.
Did he mind?
Adam Jones Jr. thinks he didn't.
In any case, this isn't true...
Well, with a probability of .9 it isn't.
(?<!\w\.\w.)(?<![A-Z][a-z]\.)(?<=\.|\?)\s
Try this. split your string this.You can also check demo.
http://regex101.com/r/nG1gU7/27
Ok so sentence-tokenizers are something I looked at in a little detail, using regexes, nltk, CoreNLP, spaCy. You end up writing your own and it depends on the application. This stuff is tricky and valuable and people don't just give their tokenizer code away. (Ultimately, tokenization is not a deterministic procedure, it's probabilistic, and also depends very heavily on your corpus or domain, e.g. legal/financial documents vs social-media posts vs Yelp reviews vs biomedical papers...)
In general you can't rely on one single Great White infallible regex, you have to write a function which uses several regexes (both positive and negative); also a dictionary of abbreviations, and some basic language parsing which knows that e.g. 'I', 'USA', 'FCC', 'TARP' are capitalized in English.
To illustrate how easily this can get seriously complicated, let's try to write you that functional spec for a deterministic tokenizer just to decide whether single or multiple period ('.'/'...') indicates end-of-sentence, or something else:
function isEndOfSentence(leftContext, rightContext)
Return False for decimals inside numbers or currency e.g. 1.23 , $1.23, "That's just my $.02" Consider also section references like 1.2.A.3.a, European date formats like 09.07.2014, IP addresses like 192.168.1.1, MAC addresses...
Return False (and don't tokenize into individual letters) for known abbreviations e.g. "U.S. stocks are falling" ; this requires a dictionary of known abbreviations. Anything outside that dictionary you will get wrong, unless you add code to detect unknown abbreviations like A.B.C. and add them to a list.
Ellipses '...' at ends of sentences are terminal, but in the middle of sentences are not. This is not as easy as you might think: you need to look at the left context and the right context, specifically is the RHS capitalized and again consider capitalized words like 'I' and abbreviations. Here's an example proving ambiguity which : She asked me to stay... I left an hour later. (Was that one sentence or two? Impossible to determine)
You may also want to write a few patterns to detect and reject miscellaneous non-sentence-ending uses of punctuation: emoticons :-), ASCII art, spaced ellipses . . . and other stuff esp. Twitter. (Making that adaptive is even harder). How do we tell if #midnight is a Twitter user, the show on Comedy Central, text shorthand, or simply unwanted/junk/typo punctuation? Seriously non-trivial.
After you handle all those negative cases, you could arbitrarily say that any isolated period followed by whitespace is likely to be an end of sentence. (Ultimately, if you really want to buy extra accuracy, you end up writing your own probabilistic sentence-tokenizer which uses weights, and training it on a specific corpus(e.g. legal texts, broadcast media, StackOverflow, Twitter, forums comments etc.)) Then you have to manually review exemplars and training errors. See Manning and Jurafsky book or Coursera course [a].
Ultimately you get as much correctness as you are prepared to pay for.
All of the above is clearly specific to the English-language/ abbreviations, US number/time/date formats. If you want to make it country- and language-independent, that's a bigger proposition, you'll need corpora, native-speaking people to label and QA it all, etc.
All of the above is still only ASCII, which is practically speaking only 96 characters. Allow the input to be Unicode, and things get harder still (and the training-set necessarily must be either much bigger or much sparser)
In the simple (deterministic) case, function isEndOfSentence(leftContext, rightContext) would return boolean, but in the more general sense, it's probabilistic: it returns a float 0.0-1.0 (confidence level that that particular '.' is a sentence end).
References: [a] Coursera video: "Basic Text Processing 2-5 - Sentence Segmentation - Stanford NLP - Professor Dan Jurafsky & Chris Manning" [UPDATE: an unofficial version used to be on YouTube, was taken down]
Try to split the input according to the spaces rather than a dot or ?, if you do like this then the dot or ? won't be printed in the final result.
>>> import re
>>> s = """Mr. Smith bought cheapsite.com for 1.5 million dollars, i.e. he paid a lot for it. Did he mind? Adam Jones Jr. thinks he didn't. In any case, this isn't true... Well, with a probability of .9 it isn't."""
>>> m = re.split(r'(?<=[^A-Z].[.?]) +(?=[A-Z])', s)
>>> for i in m:
... print i
...
Mr. Smith bought cheapsite.com for 1.5 million dollars, i.e. he paid a lot for it.
Did he mind?
Adam Jones Jr. thinks he didn't.
In any case, this isn't true...
Well, with a probability of .9 it isn't.
sent = re.split('(?<!\w\.\w.)(?<![A-Z][a-z]\.)(?<=\.|\?)(\s|[A-Z].*)',text)
for s in sent:
print s
Here the regex used is : (?<!\w\.\w.)(?<![A-Z][a-z]\.)(?<=\.|\?)(\s|[A-Z].*)
First block: (?<!\w\.\w.) : this pattern searches in a negative feedback loop (?<!) for all words (\w) followed by fullstop (\.) , followed by other words (\.)
Second block: (?<![A-Z][a-z]\.): this pattern searches in a negative feedback loop for anything starting with uppercase alphabets ([A-Z]), followed by lower case alphabets ([a-z]) till a dot (\.) is found.
Third block: (?<=\.|\?): this pattern searches in a feedback loop of dot (\.) OR question mark (\?)
Fourth block: (\s|[A-Z].*): this pattern searches after the dot OR question mark from the third block. It searches for blank space (\s) OR any sequence of characters starting with a upper case alphabet ([A-Z].*).
This block is important to split if the input is as
Hello world.Hi I am here today.
i.e. if there is space or no space after the dot.
Naive approach for proper english sentences not starting with non-alphas and not containing quoted parts of speech:
import re
text = """\
Mr. Smith bought cheapsite.com for 1.5 million dollars, i.e. he paid a lot for it. Did he mind? Adam Jones Jr. thinks he didn't. In any case, this isn't true... Well, with a probability of .9 it isn't.
"""
EndPunctuation = re.compile(r'([\.\?\!]\s+)')
NonEndings = re.compile(r'(?:Mrs?|Jr|i\.e)\.\s*$')
parts = EndPunctuation.split(text)
sentence = []
for part in parts:
if len(part) and len(sentence) and EndPunctuation.match(sentence[-1]) and not NonEndings.search(''.join(sentence)):
print(''.join(sentence))
sentence = []
if len(part):
sentence.append(part)
if len(sentence):
print(''.join(sentence))
False positive splitting may be reduced by extending NonEndings a bit. Other cases will require additional code. Handling typos in a sensible way will prove difficult with this approach.
You will never reach perfection with this approach. But depending on the task it might just work "enough"...
I'm not great at regular expressions, but a simpler version, "brute force" actually, of above is
sentence = re.compile("([\'\"][A-Z]|([A-Z][a-z]*\. )|[A-Z])(([a-z]*\.[a-z]*\.)|([A-Za-z0-9]*\.[A-Za-z0-9])|([A-Z][a-z]*\. [A-Za-z]*)|[^\.?]|[A-Za-z])*[\.?]")
which means
start acceptable units are '[A-Z] or "[A-Z]
please note, most regular expressions are greedy so the order is very important when we do |(or). That's, why I have written i.e. regular expression first, then is come forms like Inc.
Try this:
(?<!\b(?:[A-Z][a-z]|\d|[i.e]))\.(?!\b(?:com|\d+)\b)
I wrote this taking into consideration smci's comments above. It is a middle-of-the-road approach that doesn't require external libraries and doesn't use regex. It allows you to provide a list of abbreviations and accounts for sentences ended by terminators in wrappers, such as a period and quote: [.", ?', .)].
abbreviations = {'dr.': 'doctor', 'mr.': 'mister', 'bro.': 'brother', 'bro': 'brother', 'mrs.': 'mistress', 'ms.': 'miss', 'jr.': 'junior', 'sr.': 'senior', 'i.e.': 'for example', 'e.g.': 'for example', 'vs.': 'versus'}
terminators = ['.', '!', '?']
wrappers = ['"', "'", ')', ']', '}']
def find_sentences(paragraph):
end = True
sentences = []
while end > -1:
end = find_sentence_end(paragraph)
if end > -1:
sentences.append(paragraph[end:].strip())
paragraph = paragraph[:end]
sentences.append(paragraph)
sentences.reverse()
return sentences
def find_sentence_end(paragraph):
[possible_endings, contraction_locations] = [[], []]
contractions = abbreviations.keys()
sentence_terminators = terminators + [terminator + wrapper for wrapper in wrappers for terminator in terminators]
for sentence_terminator in sentence_terminators:
t_indices = list(find_all(paragraph, sentence_terminator))
possible_endings.extend(([] if not len(t_indices) else [[i, len(sentence_terminator)] for i in t_indices]))
for contraction in contractions:
c_indices = list(find_all(paragraph, contraction))
contraction_locations.extend(([] if not len(c_indices) else [i + len(contraction) for i in c_indices]))
possible_endings = [pe for pe in possible_endings if pe[0] + pe[1] not in contraction_locations]
if len(paragraph) in [pe[0] + pe[1] for pe in possible_endings]:
max_end_start = max([pe[0] for pe in possible_endings])
possible_endings = [pe for pe in possible_endings if pe[0] != max_end_start]
possible_endings = [pe[0] + pe[1] for pe in possible_endings if sum(pe) > len(paragraph) or (sum(pe) < len(paragraph) and paragraph[sum(pe)] == ' ')]
end = (-1 if not len(possible_endings) else max(possible_endings))
return end
def find_all(a_str, sub):
start = 0
while True:
start = a_str.find(sub, start)
if start == -1:
return
yield start
start += len(sub)
I used Karl's find_all function from this entry: Find all occurrences of a substring in Python
My example is based on the example of Ali, adapted to Brazilian Portuguese. Thanks Ali.
ABREVIACOES = ['sra?s?', 'exm[ao]s?', 'ns?', 'nos?', 'doc', 'ac', 'publ', 'ex', 'lv', 'vlr?', 'vls?',
'exmo(a)', 'ilmo(a)', 'av', 'of', 'min', 'livr?', 'co?ls?', 'univ', 'resp', 'cli', 'lb',
'dra?s?', '[a-z]+r\(as?\)', 'ed', 'pa?g', 'cod', 'prof', 'op', 'plan', 'edf?', 'func', 'ch',
'arts?', 'artigs?', 'artg', 'pars?', 'rel', 'tel', 'res', '[a-z]', 'vls?', 'gab', 'bel',
'ilm[oa]', 'parc', 'proc', 'adv', 'vols?', 'cels?', 'pp', 'ex[ao]', 'eg', 'pl', 'ref',
'[0-9]+', 'reg', 'f[ilí]s?', 'inc', 'par', 'alin', 'fts', 'publ?', 'ex', 'v. em', 'v.rev']
ABREVIACOES_RGX = re.compile(r'(?:{})\.\s*$'.format('|\s'.join(ABREVIACOES)), re.IGNORECASE)
def sentencas(texto, min_len=5):
# baseado em https://stackoverflow.com/questions/25735644/python-regex-for-splitting-text-into-sentences-sentence-tokenizing
texto = re.sub(r'\s\s+', ' ', texto)
EndPunctuation = re.compile(r'([\.\?\!]\s+)')
# print(NonEndings)
parts = EndPunctuation.split(texto)
sentencas = []
sentence = []
for part in parts:
txt_sent = ''.join(sentence)
q_len = len(txt_sent)
if len(part) and len(sentence) and q_len >= min_len and \
EndPunctuation.match(sentence[-1]) and \
not ABREVIACOES_RGX.search(txt_sent):
sentencas.append(txt_sent)
sentence = []
if len(part):
sentence.append(part)
if sentence:
sentencas.append(''.join(sentence))
return sentencas
Full code in: https://github.com/luizanisio/comparador_elastic
If you want to break up sentences at 3 periods (not sure if this is what you want) you can use this regular expresion:
import re
text = """\
Mr. Smith bought cheapsite.com for 1.5 million dollars, i.e. he paid a lot for it. Did he mind? Adam Jones Jr. thinks he didn't. In any case, this isn't true... Well, with a probability of .9 it isn't.
"""
sentences = re.split(r'\.{3}', text)
for stuff in sentences:
print(stuff)

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