I am trying to process various texts by regex and NLTK of python -which is at http://www.nltk.org/book-. I am trying to create a random text generator and I am having a slight problem. Firstly, here is my code flow:
Enter a sentence as input -this is called trigger string, is assigned to a variable-
Get longest word in trigger string
Search all Project Gutenberg database for sentences that contain this word -regardless of uppercase lowercase-
Return the longest sentence that has the word I spoke about in step 3
Append the sentence in Step 1 and Step4 together
Assign the sentence in Step 4 as the new 'trigger' sentence and repeat the process. Note that I have to get the longest word in second sentence and continue like that and so on-
So far, I have been able to do this only once. When I try to keep this to continue, the program only keeps printing the first sentence my search yields. It should actually look for the longest word in this new sentence and keep applying my code flow described above.
Below is my code along with a sample input/output :
Sample input
"Thane of code"
Sample output
"Thane of code Norway himselfe , with terrible numbers , Assisted by that most disloyall Traytor , The Thane of Cawdor , began a dismall Conflict , Till that Bellona ' s Bridegroome , lapt in proofe , Confronted him with selfe - comparisons , Point against Point , rebellious Arme ' gainst Arme , Curbing his lauish spirit : and to conclude , The Victorie fell on vs"
Now this should actually take the sentence that starts with 'Norway himselfe....' and look for the longest word in it and do the steps above and so on but it doesn't. Any suggestions? Thanks.
import nltk
from nltk.corpus import gutenberg
triggerSentence = raw_input("Please enter the trigger sentence: ")#get input str
split_str = triggerSentence.split()#split the sentence into words
longestLength = 0
longestString = ""
montyPython = 1
while montyPython:
#code to find the longest word in the trigger sentence input
for piece in split_str:
if len(piece) > longestLength:
longestString = piece
longestLength = len(piece)
listOfSents = gutenberg.sents() #all sentences of gutenberg are assigned -list of list format-
listOfWords = gutenberg.words()# all words in gutenberg books -list format-
# I tip my hat to Mr.Alex Martelli for this part, which helps me find the longest sentence
lt = longestString.lower() #this line tells you whether word list has the longest word in a case-insensitive way.
longestSentence = max((listOfWords for listOfWords in listOfSents if any(lt == word.lower() for word in listOfWords)), key = len)
#get longest sentence -list format with every word of sentence being an actual element-
longestSent=[longestSentence]
for word in longestSent:#convert the list longestSentence to an actual string
sstr = " ".join(word)
print triggerSentence + " "+ sstr
triggerSentence = sstr
How about this?
You find longest word in trigger
You find longest word in the longest sentence containing word found in 1.
The word of 1. is the longest word of the sentence of 2.
What happens? Hint: answer starts with "Infinite". To correct the problem you could find set of words in lower case to be useful.
BTW when you think MontyPython becomes False and the program finish?
Rather than searching the entire corpus each time, it may be faster to construct a single map from word to the longest sentence containing that word. Here's my (untested) attempt to do this.
import collections
from nltk.corpus import gutenberg
def words_in(sentence):
"""Generate all words in the sentence (lower-cased)"""
for word in sentence.split():
word = word.strip('.,"\'-:;')
if word:
yield word.lower()
def make_sentence_map(books):
"""Construct a map from words to the longest sentence containing the word."""
result = collections.defaultdict(str)
for book in books:
for sentence in book:
for word in words_in(sentence):
if len(sentence) > len(result[word]):
result[word] = sent
return result
def generate_random_text(sentence, sentence_map):
while True:
yield sentence
longest_word = max(words_in(sentence), key=len)
sentence = sentence_map[longest_word]
sentence_map = make_sentence_map(gutenberg.sents())
for sentence in generate_random_text('Thane of code.', sentence_map):
print sentence
Mr. Hankin's answer is more elegant, but the following is more in keeping with the approach you began with:
import sys
import string
import nltk
from nltk.corpus import gutenberg
def longest_element(p):
"""return the first element of p which has the greatest len()"""
max_len = 0
elem = None
for e in p:
if len(e) > max_len:
elem = e
max_len = len(e)
return elem
def downcase(p):
"""returns a list of words in p shifted to lower case"""
return map(string.lower, p)
def unique_words():
"""it turns out unique_words was never referenced so this is here
for pedagogy"""
# there are 2.6 million words in the gutenburg corpus but only ~42k unique
# ignoring case, let's pare that down a bit
for word in gutenberg.words():
words.add(word.lower())
print 'gutenberg.words() has', len(words), 'unique caseless words'
return words
print 'loading gutenburg corpus...'
sentences = []
for sentence in gutenberg.sents():
sentences.append(downcase(sentence))
trigger = sys.argv[1:]
target = longest_element(trigger).lower()
last_target = None
while target != last_target:
matched_sentences = []
for sentence in sentences:
if target in sentence:
matched_sentences.append(sentence)
print '===', target, 'matched', len(matched_sentences), 'sentences'
longestSentence = longest_element(matched_sentences)
print ' '.join(longestSentence)
trigger = longestSentence
last_target = target
target = longest_element(trigger).lower()
Given your sample sentence though, it reaches fixation in two cycles:
$ python nltkgut.py Thane of code
loading gutenburg corpus...
=== target thane matched 24 sentences
norway himselfe , with terrible
numbers , assisted by that most
disloyall traytor , the thane of
cawdor , began a dismall conflict ,
till that bellona ' s bridegroome ,
lapt in proofe , confronted him with
selfe - comparisons , point against
point , rebellious arme ' gainst arme
, curbing his lauish spirit : and to
conclude , the victorie fell on vs
=== target bridegroome matched 1 sentences
norway himselfe , with
terrible numbers , assisted by that
most disloyall traytor , the thane of
cawdor , began a dismall conflict ,
till that bellona ' s bridegroome ,
lapt in proofe , confronted him with
selfe - comparisons , point against
point , rebellious arme ' gainst arme
, curbing his lauish spirit : and to
conclude , the victorie fell on vs
Part of the trouble with the response to the last problem is that it did what you asked, but you asked a more specific question than you wanted an answer to. Thus the response got bogged down in some rather complicated list expressions that I'm not sure you understood. I suggest that you make more liberal use of print statements and don't import code if you don't know what it does. While unwrapping the list expressions I found (as noted) that you never used the corpus wordlist. Functions are a help also.
You are assigning "split_str" outside of the loop, so it gets the original value and then keeps it. You need to assign it at the beginning of the while loop, so it changes each time.
import nltk
from nltk.corpus import gutenberg
triggerSentence = raw_input("Please enter the trigger sentence: ")#get input str
longestLength = 0
longestString = ""
montyPython = 1
while montyPython:
#so this is run every time through the loop
split_str = triggerSentence.split()#split the sentence into words
#code to find the longest word in the trigger sentence input
for piece in split_str:
if len(piece) > longestLength:
longestString = piece
longestLength = len(piece)
listOfSents = gutenberg.sents() #all sentences of gutenberg are assigned -list of list format-
listOfWords = gutenberg.words()# all words in gutenberg books -list format-
# I tip my hat to Mr.Alex Martelli for this part, which helps me find the longest sentence
lt = longestString.lower() #this line tells you whether word list has the longest word in a case-insensitive way.
longestSentence = max((listOfWords for listOfWords in listOfSents if any(lt == word.lower() for word in listOfWords)), key = len)
#get longest sentence -list format with every word of sentence being an actual element-
longestSent=[longestSentence]
for word in longestSent:#convert the list longestSentence to an actual string
sstr = " ".join(word)
print triggerSentence + " "+ sstr
triggerSentence = sstr
Related
I have a project where I need to do the following:
User inputs a sentence
intersect sentence with list for matching strings
replace one of the matching strings with a new string
print the original sentence featuring the replacement
fruits = ['Quince', 'Raisins', 'Raspberries', 'Rhubarb', 'Strawberries', 'Tangelo', 'Tangerines']
# Asks the user for a sentence.
random_sentence = str(input('Please enter a random sentence:\n')).title()
stripped_sentence = random_sentence.strip(',.!?')
split_sentence = stripped_sentence.split()
# Solve for single word fruit names
sentence_intersection = set(fruits).intersection(split_sentence)
# Finds and replaces at least one instance of a fruit in the sentence with “Brussels Sprouts”.
intersection_as_list = list(sentence_intersection)
intersection_as_list[-1] = 'Brussels Sprouts'
Example Input: "I would like some raisins and strawberries."
Expected Output: "I would like some raisins and Brussels Sprouts."
But I can't figure out how to join the string back together after making the replacement. Any help is appreciated!
You can do it with a regex:
(?i)Quince|Raisins|Raspberries|Rhubarb|Strawberries|Tangelo|Tangerines
This pattern will match any of your words in a case insensitive way (?i).
In Python, you can obtain that pattern by joining your fruits into a single string. Then you can use the re.sub function to replace your first matching word with "Brussels Sprouts".
import re
fruits = ['Quince', 'Raisins', 'Raspberries', 'Rhubarb', 'Strawberries', 'Tangelo', 'Tangerines']
# Asks the user for a sentence.
#random_sentence = str(input('Please enter a random sentence:\n')).title()
sentence = "I would like some raisins and strawberries."
pattern = '(?i)' + '|'.join(fruits)
replacement = 'Brussels Sprouts'
print(re.sub(pattern, replacement, sentence, 1))
Output:
I would like some Brussels Sprouts and strawberries.
Check the Python demo here.
Create a set of lowercase possible word matches, then use a replacement function.
If a word is found, clear the set, so replacement works only once.
import re
fruits = ['Quince', 'Raisins', 'Raspberries', 'Rhubarb', 'Strawberries', 'Tangelo', 'Tangerines']
fruit_set = {x.lower() for x in fruits}
s = "I would like some raisins and strawberries."
def repfunc(m):
w = m.group(1)
if w.lower() in fruit_set:
fruit_set.clear()
return "Brussel Sprouts"
else:
return w
print(re.sub(r"(\w+)",repfunc,s))
prints:
I would like some Brussel Sprouts and strawberries.
That method has the advantage of being O(1) on lookup. If there are a lot of possible words it will beat the linear search that | performs when testing word after word.
It's simpler to replace just the first occurrence, but replacing the last occurrence, or a random occurrence is also doable. First you have to count how many fruits are in the sentence, then decide which replacement is effective in a second pass.
like this: (not very beautiful, using a lot of globals and all)
total = 0
def countfunc(m):
global total
w = m.group(1)
if w.lower() in fruit_set:
total += 1
idx = 0
def repfunc(m):
global idx
w = m.group(1)
if w.lower() in fruit_set:
if total == idx+1:
return "Brussel Sprouts"
else:
idx += 1
return w
else:
return w
re.sub(r"(\w+)",countfunc,s)
print(re.sub(r"(\w+)",repfunc,s))
first sub just counts how many fruits would match, then the second function replaces only when the counter matches. Here last occurrence is selected.
I am working on removing similar phrases in a list, but I have hit a small roadblock.
I have sentences and phrases, phrases are related to the sentence. All phrases of a sentence are in a single list.
Let the phrase list be : p=[['This is great','is great','place for drinks','for drinks'],['Tonight is a good','good night','is a good','for movies']]
I want my output to be [['This is great','place for drinks'],['Tonight is a good','for movies']]
Basically, I want to get all the longest unique phrases of a list.
I took a look at fuzzywuzzy library, but I am unable to get around to a good solution.
here is my code :
def remove_dup(arr, threshold=80):
ret_arr =[]
for item in arr:
if item[1]<threshold:
ret_arr.append(item[0])
return ret_arr
def find_important(sents=sents, phrase=phrase):
import os, random
from fuzzywuzzy import process, fuzz
all_processed = [] #final array to be returned
for i in range(len(sents)):
new_arr = [] #reshaped phrases for a single sentence
for item in phrase[i]:
new_arr.append(item)
new_arr.sort(reverse=True, key=lambda x : len(x)) #sort with highest length
important = [] #array to store terms
important = process.extractBests(new_arr[0], new_arr) #to get levenshtein distance matches
to_proc = remove_dup(important) #remove_dup removes all relatively matching terms.
to_proc.append(important[0][0]) #the term with highest match is obviously the important term.
all_processed.append(to_proc) #add non duplicates to all_processed[]
return all_processed
Can someone point out what I am missing, or what is a better way to do this?
Thanks in advance!
I would use the difference between each phrase and all the other phrases.
If a phrase has at least one different word compared to all the other phrases then it's unique and should be kept.
I've also made it robust to exact matches and added spaces
sentences = [['This is great','is great','place for drinks','for drinks'],
['Tonight is a good','good night','is a good','for movies'],
['Axe far his favorite brand for deodorant body spray',' Axe far his favorite brand for deodorant spray','Axe is']]
new_sentences = []
s = " "
for phrases in sentences :
new_phrases = []
phrases = [phrase.split() for phrase in phrases]
for i in range(len(phrases)) :
phrase = phrases[i]
if all([len(set(phrase).difference(phrases[j])) > 0 or i == j for j in range(len(phrases))]) :
new_phrases.append(phrase)
new_phrases = [s.join(phrase) for phrase in new_phrases]
new_sentences.append(new_phrases)
print(new_sentences)
Output:
[['This is great', 'place for drinks'],
['Tonight is a good', 'good night', 'for movies'],
['Axe far his favorite brand for deodorant body spray', 'Axe is']]
Is there a way to replace a word within a string without using a "string replace function," e.g., string.replace(string,word,replacement).
[out] = forecast('This snowy weather is so cold.','cold','awesome')
out => 'This snowy weather is so awesome.
Here the word cold is replaced with awesome.
This is from my MATLAB homework which I am trying to do in python. When doing this in MATLAB we were not allowed to us strrep().
In MATLAB, I can use strfind to find the index and work from there. However, I noticed that there is a big difference between lists and strings. Strings are immutable in python and will likely have to import some module to change it to a different data type so I can work with it like how I want to without using a string replace function.
just for fun :)
st = 'This snowy weather is so cold .'.split()
given_word = 'awesome'
for i, word in enumerate(st):
if word == 'cold':
st.pop(i)
st[i - 1] = given_word
break # break if we found first word
print(' '.join(st))
Here's another answer that might be closer to the solution you described using MATLAB:
st = 'This snow weather is so cold.'
given_word = 'awesome'
word_to_replace = 'cold'
n = len(word_to_replace)
index_of_word_to_replace = st.find(word_to_replace)
print st[:index_of_word_to_replace]+given_word+st[index_of_word_to_replace+n:]
You can convert your string into a list object, find the index of the word you want to replace and then replace the word.
sentence = "This snowy weather is so cold"
# Split the sentence into a list of the words
words = sentence.split(" ")
# Get the index of the word you want to replace
word_to_replace_index = words.index("cold")
# Replace the target word with the new word based on the index
words[word_to_replace_index] = "awesome"
# Generate a new sentence
new_sentence = ' '.join(words)
Using Regex and a list comprehension.
import re
def strReplace(sentence, toReplace, toReplaceWith):
return " ".join([re.sub(toReplace, toReplaceWith, i) if re.search(toReplace, i) else i for i in sentence.split()])
print(strReplace('This snowy weather is so cold.', 'cold', 'awesome'))
Output:
This snowy weather is so awesome.
I have used the following code to extract a sentence from file(the sentence should contain some or all of the search keywords)
search_keywords=['mother','sing','song']
with open('text.txt', 'r') as in_file:
text = in_file.read()
sentences = text.split(".")
for sentence in sentences:
if (all(map(lambda word: word in sentence, search_keywords))):
print sentence
The problem with the above code is that it does not print the required sentence if one of the search keywords do not match with the sentence words. I want a code that prints the sentence containing some or all of the search keywords. It would be great if the code can also search for a phrase and extract the corresponding sentence.
It seems like you want to count the number of search_keyboards in each sentence. You can do this as follows:
sentences = "My name is sing song. I am a mother. I am happy. You sing like my mother".split(".")
search_keywords=['mother','sing','song']
for sentence in sentences:
print("{} key words in sentence:".format(sum(1 for word in search_keywords if word in sentence)))
print(sentence + "\n")
# Outputs:
#2 key words in sentence:
#My name is sing song
#
#1 key words in sentence:
# I am a mother
#
#0 key words in sentence:
# I am happy
#
#2 key words in sentence:
# You sing like my mother
Or if you only want the sentence(s) that have the most matching search_keywords, you can make a dictionary and find the maximum values:
dct = {}
for sentence in sentences:
dct[sentence] = sum(1 for word in search_keywords if word in sentence)
best_sentences = [key for key,value in dct.items() if value == max(dct.values())]
print("\n".join(best_sentences))
# Outputs:
#My name is sing song
# You sing like my mother
If I understand correctly, you should be using any() instead of all().
if (any(map(lambda word: word in sentence, search_keywords))):
print sentence
So you want to find sentences that contain at least one keyword. You can use any() instead of all().
EDIT:
If you want to find the sentence which contains the most keywords:
sent_words = []
for sentence in sentences:
sent_words.append(set(sentence.split()))
num_keywords = [len(sent & set(search_keywords)) for sent in sent_words]
# Find only one sentence
ind = num_keywords.index(max(num_keywords))
# Find all sentences with that number of keywords
ind = [i for i, x in enumerate(num_keywords) if x == max(num_keywords)]
So i have a string which i have split and from that created a list in Python.
I now need to find the location of a certain word in that list.
The problem that im having: the word im looking for appears twice in the list. The code i have brings back the location of the first word however it doesnt continue and bring back the other location.
Example: The main reason that i play football is because i love football.
It will find the first FOOTBALL but not the second. Help!!
This is the code i have :
sentence = " The main reson that i play football is because i love football"
sentence = sentence.split()
print(sentence.index("football"))
In the below snippet i will contain indices of 'football' in the list.
s = 'The main reason that i play football is because i love football.'
words = s.split()
i=[ind for ind,p in enumerate(words) if p=='football']
import re
looking_for = 'football'
in_text = 'The main reason that i play football is because i love football.'
without_punctuation = re.sub('[^a-zA-Z ]', '', in_text)
words = without_punctuation.split(' ')
for i, w in enumerate(words):
if w == looking_for:
print(i)
But of course. Punctuation is going to be an issue, like here (with 'football.') – so I've now stripped most of it.
Try this
def findall(list_in, search_str):
output=[]
last_index=0
while True:
try:
find=list_in[last_index:].index(search_str)+last_index
output.append(find)
last_index= find+1;
except:
break
return output
output is a list of the indices where search_str can be found in list_in