Develop Reference

string.punctuation fails to remove certain characters from a string

My aim is to remove all punctuations from a string so that I can then get the frequency of each word in the string.
My string is:
WASHINGTON—Coming to the realization in front of millions of viewers
during the broadcast of his show, a horrified Tucker Carlson stated,
‘I…I am the mainstream media’ Wednesday as he began spiraling live on
air. “We’ve discovered evidence of rampant voter fraud, and the
president has every right to call for an investigation even if the
mainstream media thinks...” said Carlson, who trailed off, stared down
at his shaking hands, and felt a sudden ringing in his ears as he
looked back up and zeroed in on the production crew surrounding him.
“The media says…wait. Those liars on TV will try to tell you…oh God.
We’re the number-one program on cable news, aren’t we? Fox News…Fox
‘News.’ It’s the media. It’s me. This can’t be. No, no, no, no. Jesus
Christ, I make $6 million a year. Get that camera off me!” At press
time, Carlson had torn the microphone from his lapel and fled the set
in panic.
source: https://www.theonion.com/i-i-am-the-mainstream-media-realizes-horrified-tuc-1845646901
I want to remove all punctuations from it. I do that like this -
s.translate(str.maketrans('', '', string.punctuation))
This is the output -
WASHINGTON—Coming to the realization in front of millions of viewers
during the broadcast of his show a horrified Tucker Carlson stated
‘I…I am the mainstream media’ Wednesday as he began spiraling live on
air “We’ve discovered evidence of rampant voter fraud and the
president has every right to call for an investigation even if the
mainstream media thinks” said Carlson who trailed off stared down at
his shaking hands and felt a sudden ringing in his ears as he looked
back up and zeroed in on the production crew surrounding him “The
media says…wait Those liars on TV will try to tell you…oh God We’re
the numberone program on cable news aren’t we Fox News…Fox ‘News’ It’s
the media It’s me This can’t be No no no no Jesus Christ I make 6
million a year Get that camera off me” At press time Carlson had torn
the microphone from his lapel and fled the set in panic
As you can see that characters/ string like ", — and ... still exist. Am I incorrectly expecting them to be removed too? If the output is correct then how can I NOT differentiate between "`News`" and "News"?

>>> import string
>>> "“" in string.punctuation
False
>>> "—" in string.punctuation
False
Welcome to the wonderful world of Unicode where, among many other things, … is not three concatenated full stop periods and :
>>> import unicodedata
>>> unicodedata.name('—')
'EM DASH'
is not a hyphen.
How you want to handle the full scope of what could be considered 'punctuation' across the Unicode table is probably out of scope for this question, but you could either come up with your own ad-hoc list or use a third-party library designed for that type of text manipulation. Here is one such approach:
Best way to strip punctuation from a string

I added the list of characters you can remove from string by using your implementation.
>>> string.punctuation
'!"#$%&\'()*+,-./:;<=>?#[\\]^_`{|}~'
You can check this implementation to remove all special characters and keep whitespaces
''.join(e for e in s if e.isalnum() or e == ' ')

It looks like the … and a couple of the other characters you are having trouble with are special Unicode characters. A workaround is to use string.isalpha(), which tells you whether the characters of a string are part of the alphabet or not.
result = ""
for x in string:
if x.isalpha() or x == " ":
result = result + x

Splitting A List At Certain Characer

say I have a list that goes something like this:
['Try not to become a man of success, but rather try to become a man of value.
\n', 'Look deep into nature, and then you will understand everything
better.\n', 'The true sign of intelligence is not knowledge but imagination.
\n', 'We cannot solve our problems with the same thinking we used when we
created them. \n', 'Weakness of attitude becomes weakness of character.\n',
"You can't blame gravity for falling in love. \n", 'The difference between
stupidity and genius is that genius has its limits. \n']
How would I go about splitting this list into sub-lists at every newline?
How do I turn the output above to my desired output below?
['Try not to become a man of success, but rather try to become a man of value.']
['Look deep into nature, and then you will understand everything better'] ['The true sign of intelligence is not knowledge but imagination.]

Your expected result seems like a list of item where each item is a list containing a single element composed of the list item stripped of whitespaces, something that can be achieved using:
result = [[line.strip()] for line in lines]

Removing "\n"s when printing sentences from text file in python?

I am trying to print a list of sentences from a text file (one of the Project Gutenberg eBooks). When I print the file as a single string string it looks fine:
file = open('11.txt','r+')
alice = file.read()
print(alice[:500])
Output is:
ALICE'S ADVENTURES IN WONDERLAND
Lewis Carroll
THE MILLENNIUM FULCRUM EDITION 3.0
CHAPTER I. Down the Rabbit-Hole
Alice was beginning to get very tired of sitting by her sister on the
bank, and of having nothing to do: once or twice she had peeped into the
book her sister was reading, but it had no pictures or conversations in
it, 'and what is the use of a book,' thought Alice 'without pictures or
conversations?'
So she was considering in her own mind (as well as she could, for the
hot d
Now, when I split it into sentences (The assignment was specifically to do this by "splitting at the periods," so it's a very simplified split), I get this:
>>> print(sentences[:5])
["ALICE'S ADVENTURES IN WONDERLAND\n\nLewis Carroll\n\nTHE MILLENNIUM FULCRUM EDITION 3", '0\n\n\n\n\nCHAPTER I', " Down the Rabbit-Hole\n\nAlice was beginning to get very tired of sitting by her sister on the\nbank, and of having nothing to do: once or twice she had peeped into the\nbook her sister was reading, but it had no pictures or conversations in\nit, 'and what is the use of a book,' thought Alice 'without pictures or\nconversations?'\n\nSo she was considering in her own mind (as well as she could, for the\nhot day made her feel very sleepy and stupid), whether the pleasure\nof making a daisy-chain would be worth the trouble of getting up and\npicking the daisies, when suddenly a White Rabbit with pink eyes ran\nclose by her", "\n\nThere was nothing so VERY remarkable in that; nor did Alice think it so\nVERY much out of the way to hear the Rabbit say to itself, 'Oh dear!\nOh dear! I shall be late!' (when she thought it over afterwards, it\noccurred to her that she ought to have wondered at this, but at the time\nit all seemed quite natural); but when the Rabbit actually TOOK A WATCH\nOUT OF ITS WAISTCOAT-POCKET, and looked at it, and then hurried on,\nAlice started to her feet, for it flashed across her mind that she had\nnever before seen a rabbit with either a waistcoat-pocket, or a watch\nto take out of it, and burning with curiosity, she ran across the field\nafter it, and fortunately was just in time to see it pop down a large\nrabbit-hole under the hedge", '\n\nIn another moment down went Alice after it, never once considering how\nin the world she was to get out again']
Where do the extra "\n" characters come from and how can I remove them?

If you want to replace all the newlines with one space, do this:
import re
new_sentences = [re.sub(r'\n+', ' ', s) for s in sentences]

You may not want to use regex, but I would do:
import re
new_sentences = []
for s in sentences:
new_sentences.append(re.sub(r'\n{2,}', '\n', s))
This should replace all instances of two or more '\n' with a single newline, so you still have newlines, but don't have "extra" newlines.
If you want to avoid creating a new list, and instead modify the existing one (credit to #gavriel and Andrew L.: I hadn't thought of using enumerate when I first posted my answer):
import re
for i, s in enumerate(sentences):
sentences[i] = re.sub(r'\n{2,}', '\n', s)
The extra newlines aren't really extra, by which I mean they are meant to be there and are visible in the text in your question: the more '\n' there are, the more space there is visible between the lines of text (i.e., one between the chapter heading and the first paragraph, and many between the edition and the chapter heading.

You'll understand where the \n characters come from with this little example:
alice = """ALICE'S ADVENTURES IN WONDERLAND
Lewis Carroll
THE MILLENNIUM FULCRUM EDITION 3.0
CHAPTER I. Down the Rabbit-Hole
Alice was beginning to get very tired of sitting by her sister on the
bank, and of having nothing to do: once or twice she had peeped into the
book her sister was reading, but it had no pictures or conversations in
it, 'and what is the use of a book,' thought Alice 'without pictures or
conversations?'
So she was considering in her own mind (as well as she could, for the
hot d"""
print len(alice.split("."))
print len(alice.split("\n"))
It all depends the way you're splitting your text, the above example will give this output:
3
19
Which means there are 3 substrings if you were to split the text using . or 19 substrings if you splitted using \n as separator. You can read more about str.split
In your case you've splitted your text using ., so the 3 substrings will contain multiple newlines characters \n, to get rid of them you can either split these substrings again or just get rid of them using str.replace

The text uses newlines to delimit sentences as well as fullstops. You have an issue where just replacing the new line characters with an empty string will result in having words without spaces between them. Before you split alice by '.', I would use something along the lines of #elethan's solution to replace all of the multiple new lines in alice with a '.' Then you could do alice.split('.') and all of the sentences separated with multiple new lines would be split appropriately along with the sentences separated with . initially.
Then your only issue is the decimal point in the version number.

file = open('11.txt','r+')
file.read().split('\n')

Split Sentence on Punctuation or Camel-Case

I have a very long string in python and i'm trying to break it up into a list of sentences. Only some of these sentences are missing puntuation and spaces between them.
Example
I have 9 sheep in my garageVideo games are super cool.
I can't figure out the regex to separate the two! It's drive me nuts.
There are properly punctuated sentences as well, so I thought i'd make several different regex patterns, each splitting off different styles of combination.
Input
I have 9 sheep in my garageVideo games are super cool. Some peanuts can sing, though they taste a whole lot better than they sound!
Output
['I have 9 sheep in my garage',
'Video games are super cool.'
'Some peanuts can sing, though they taste a whole lot better than they sound!']
Thanks!

Position Split: Use the regex module
I will give you both a "Split" and a "Match All" option. Let's start with "Split".
In many engines, but not Python's re module, you can split at a position defined by a zero-width match.
In Python, to split on a position, I would use Matthew Barnett's outstanding regex module, whose features far outstrip those of Python's default re engine. That is my default regex engine in Python.
With your input, you can use this regex:
(?V1)(?<=[a-z])(?=[A-Z])|(?<=[.!?]) +(?=[A-Z])
Note that if you had strangely-formatted acronyms such as B. B. C., we would need to tweak this.
Sample Python Code:
string = "I have 9 sheep in my garageVideo games are super cool. Some peanuts can sing, though they taste a whole lot better than they sound!"
result = regex.split("(?V1)(?<=[a-z])(?=[A-Z])|(?<=[.!?]) +(?=[A-Z])", string)
print(result)
Output:
['I have 9 sheep in my garage',
'Video games are super cool.',
'Some peanuts can sing, though they taste a whole lot better than they sound!']
Explanation
(?V1) instructs the engine to use the new behavior, where we can split on zero-width matches.
(?<=[a-z])(?=[A-Z]) matches a position where the lookbehind (?<=[a-z]) can assert that what precedes is a lower-case letter and the lookahead (?=[A-Z]) can assert that what follows is an uppercase letter.
| OR...
(?<=[.!?]) +(?=[A-Z]) matches one or more spaces + where the lookbehind (?<=[.!?]) can assert that what precedes is a dot, bang, question mark and a space, and where the lookahead (?=[A-Z]) can assert that what follows is a capital letter.
Option 2: Use findall (again with the regex module)
Since the "Split" and "Match All" operations are two sides of the same coin, you can do this:
print(regex.findall(r".+?(?:(?<=[.!?])|(?<=[a-z])(?=[A-Z]))",string))
Again, this would not work with re (which would skip the V that starts the second sentence Video).

Using regular expressions in Python

I'm struggling with the problem to cut the very first sentence from the string.
It wouldn't be such a problem if I there were no abbreviations ended with dot.
So my example is:
string = 'I like cheese, cars, etc. but my the most favorite website is stackoverflow. My new horse is called Randy.'
And the result should be:
result = 'I like cheese, cars, etc. but my the most favorite website is stackoverflow.'
Normally I would do with:
re.findall(r'^(\s*.*?\s*)(?:\.|$)', event)
but I would like to skip some pre-defined words, like above mentioned etc.
I came with couple of expression but none of them worked.

You could try NLTK's Punkt sentence tokenizer, which does this kind of thing using a real algorithm to figure out what the abbreviations are instead of your ad-hoc collection of abbreviations.
NLTK includes a pre-trained one for English; load it with:
nltk.data.load('tokenizers/punkt/english.pickle')
From the source code:
>>> sent_detector = nltk.data.load('tokenizers/punkt/english.pickle')
>>> print '\n-----\n'.join(sent_detector.tokenize(text.strip()))
Punkt knows that the periods in Mr. Smith and Johann S. Bach
do not mark sentence boundaries.
-----
And sometimes sentences
can start with non-capitalized words.
-----
i is a good variable
name.

How about looking for the first capital letter after a sentence-ending character? It's not foolproof, of course.
import re
r = re.compile("^(.+?[.?!])\s*[A-Z]")
print r.match('I like cheese, cars, etc. but my the most favorite website is stackoverflow. My new horse is called Randy.').group(1)
outputs
'I like cheese, cars, etc. but my the most favorite website is stackoverflow.'