Replace the whole string if it contains specific letters/character - python-2.7

Replace the whole string if it contains specific letters/character…
I have a text file (myFile.txt) that contains multiple lines, for example:
The hotdog
The goal
The goat
What I want to do is the following:
If any word/string in the file contains the characters 'go' then, replace it with a brand new word/string ("boat"), so the output would look like this:
The hotdog
The boat
The boat
How can I accomplish this in Python 2.7?

It sounds like you want something like this:
with open('myFile.txt', 'r+') as word_bank:
new_lines = []
for line in word_bank:
new_line = []
for word in line.strip().split():
if 'go' in word:
new_line.append('boat')
else:
new_line.append(word)
new_lines.append('%s\n' % ' '.join(new_line))
word_bank.truncate(0)
word_bank.seek(0)
word_bank.writelines(new_lines)
Open the file for reading and writing, iterate through it splitting each line into component words and looking for instances of 'go' to replace. Keep in list because you do not want to modify something you're iterating over. You will have a bad time. Once constructed, truncate the file (erase it) and write what you came up with. Notice I switched to sticking an explicit '\n' on the end because writelines will not do that for you.

Related

How to split a string based on empty/blank lines?

I'm writing a c++ application (Qt Widgets) that is supposed to parse an .srt subtitle file. Each part of the file is separated by an empty line, like this:
1
00:00:08,000 --> 00:00:11,000
[Line]
2
00:00:56,034 --> 00:00:57,492
[Line]
[Another line]
3
00:01:13,676 --> 00:01:15,420
[Line]
Basically, I want to read the entire file to a QString, and split it by empty lines into QString array, each item containing one of those sections like this:
2
00:00:56,034 --> 00:00:57,492
[Line]
[Another line]
However, I cannot figure out how to do this. I tried splitting the string by \r and \n, but that split everything into separate lines, not by empty lines.
This is the routine I had in mind to get the data from the .srt file:
Read all of the contents of the file to a QString (named something along the lines of content).
Split the QString by empty lines, and append to a QStringList (named something along the lines of sections).
For each item in sections, split the second line by the --> identifier, and assign indexes 0 and 1 to QString variables called startTime, and endTime, respectively.
Take the rest of the lines (everything after line 2 is the subtitle text), and append them to a QString called subtitleText.
Add all the gathered information to an SrtSubtitle instance, and append it to QList<SrtSubtitle>
How can I achieve this?
New lines are usually represented as \n.
To split the string when there are 2 new lines without anything between them, you can use \n\n as delimiter.
I would improve upon ziarra's answer. You certainly want the solution to be robust and work also with Windows line endings which are "\r\n" instead of "\n". In that case ziarra's solution would not suffice.
So my proposal is to do it in two steps:
replace all occurrences of "\r\n" with "\n"
split the text by "\n\n" (as ziarra suggests)

Making a text file which will contain my list items and applying regular expression to it

I am supposed to make a code which will read a text file containing some words with some common linguistic features. Apply some regular expression to all of the words and write one file which will have the changed words.
For now let's say my text file named abcd.txt has these words
king
sing
ping
cling
booked
looked
cooked
packed
My first question starts from here. In my simple text file how to write these words to get the above mentioned results. Shall I write them line-separated or comma separated?
This is the code provided by user palvarez.
import re
with open("new_abcd", "w+") as new, open("abcd") as original:
for word in original:
new_word = re.sub("ing$", "xyz", word)
new.write(new_word)
Can I add something like -
with open("new_abcd", "w+") as file, open("abcd") as original:
for word in original:
new_aword = re.sub("ed$", "abcd", word)
new.write(new_aword)
in the same code file? I want something like -
kabc
sabc
pabc
clabc
bookxyz
lookxyz
cookxyz
packxyz
PS - I don't know whether mentioning this is necessary or not, but I am supposed to do this for a Unicode supported script Devanagari. I didn't use it here in my examples because many of us here can't read the script. Additionally that script uses some diacritics. eg. 'का' has one consonant character 'क' and one vowel symbol 'ा' which together make 'का'. In my regular expression I need to condition the diacritics.
I think the approach you have with one word by line is better since you don't have to trouble yourself with delimiters and striping.
With a file like this:
king
sing
ping
cling
booked
looked
cooked
packed
And a code like this, using re.sub to replace a pattern:
import re
with open("new_abcd.txt", "w") as new, open("abcd.txt") as original:
for word in original:
new_word = re.sub("ing$", "xyz", word)
new_word = re.sub("ed$", "abcd", new_word)
new.write(new_word)
It creates a resulting file:
kxyz
sxyz
pxyz
clxyz
bookabcd
lookabcd
cookabcd
packabcd
I tried out with the diacritic you gave us and it seems to work fine:
print(re.sub("ा$", "ing", "का"))
>>> कing
EDIT: added multiple replacement. You can have your replacements into a list and iterate over it to do re.sub as follows.
import re
# List where first is pattern and second is replacement string
replacements = [("ing$", "xyz"), ("ed$", "abcd")]
with open("new_abcd.txt", "w") as new, open("abcd.txt") as original:
for word in original:
new_word = word
for pattern, replacement in replacements:
new_word = re.sub(pattern, replacement, word)
if new_word != word:
break
new.write(new_word)
This limits one modification per word, only the first that modifies the word is taken.
It is recommended that for starters, utilize the with context manager to open your file, this way you do not need to explicitly close the file once you are done with it.
Another added advantage is then you are able to process the file line by line, this will be very useful if you are working with larger sets of data. Writing them in a single line or csv format will then all depend on the requirement of your output and how you would want to further process them.
As an example, to read from a file and say substitute a substring, you can use re.sub.
import re
with open('abcd.txt', 'r') as f:
for line in f:
#do something here
print(re.sub("ing$",'ring',line.strip()))
>>
kring
sring
pring
clring
Another nifty trick is to manage both the input and output utilizing the same context manager like:
import re
with open('abcd.txt', 'r') as f, open('out_abcd.txt', 'w') as o:
for line in f:
#notice that we add '\n' to write each output to a newline
o.write(re.sub("ing$",'ring',line.strip())+'\n')
This create an output file with your new contents in a very memory efficient way.
If you'd like to write to a csv file or any other specific formats, I highly suggest you spend sometime to understand Python's input and output functions here. If linguistics in text is what you are going for that understand encoding of different languages and further study Python's regex operations.

Python - using raw_input() to search a text document

I am trying to write a simple script that a user can enter what he/she wants to search in a specified txt file. If the word they searching is found then print it to a new text file. This is what I got so far.
import re
import os
os.chdir("C:\Python 2016 Training")
patterns = open("rtr.txt", "r")
what_directory_am_i_in = os.getcwd()
print what_directory_am_i_in
search = raw_input("What you looking for? ")
for line in patterns:
re.findall("(.*)search(.*)", line)
fo = open("test", "wb")
fo.write(line)
fo.close
This successfully creates a file called test, but the output is nothing close to what word was entered into the search variable.
Any advice appreciated.
First of all, you have not read a file
patterns = open("rtr.txt", "r")
this is a file object and not the content of file, to read the file contents you need to use
patterns.readlines()
secondly, re.findall returns a list of matched strings, so you would want to store that. You regex is also not correct as pointed by Hani, It should be
matched = re.findall("(.*)" + search + "(.*)", line)
rather it should be :
if you want the complete line
matched = re.findall(".*" + search + ".*", line)
or simply
matched = line if search in line else None
Thirdly, you don't need to keep opening your output file in the for loop. You are overwriting your file everytime in the loop so it will capture only the last result. Also remember to call the close method on the files.
Hope this helps
you are searching here for all lines that has "search" word in it
you need to get the lines that has the text you entered in the shell
so change this line
re.findall("(.*)search(.*)", line)
to
re.findall("(.*)"+search+"(.*)", line)

vim: search, capture & replace on different lines using regex

Relatively new linux/vim/regex user here. I want to use regex to search for a numerical patterns, capture it, and then use the captured value to append a string to the previous line. In other words...I have a file of format:
title: description_id
text: {en: '2. text description'}
I want to capture the values from the text field and append them to the beginning of the title field...to yield something like this:
title: q2_description_id
text: {en: '2. text description'}
I feel like I've come across a way to reference other lines in a search & replace but am having trouble finding that now. Or maybe a macro would be suitable. Any help would be appreciated...thanks!
Perhaps something like:
:%s/\(title: \)\(.*\n\)\(text: \D*\)\(\d*\)/\1q\4_\2\3\4/
Where we are searching for 4 parts:
"title: "
rest of line and \n
"text: " and everything until next digit in line
first string of consecutive digits in line
and spitting them back out, with 4) inserted between 1) and 2).
EDIT: Shorter solution by Peter in the comments:
:%s/title: \zs\ze\_.\{-}text: \D*\(\d*\)/q\1_/
Use \n for the new lines (and ^v+enter for new lines on the substitute line): A quick and not very elegant example:
:%s/title: description_id\n\ntext: {en: '\(\i*\)\(.*\)/title: q\1_description_id^Mtext: {en: '\1\2/

parse text with Matlab

I have a text file (output from an old program) that I'd like to clean. Here's an example of the file contents.
*|V|0|0|0|t|0|1|1|4|11|T4|H01||||||||||||||||||||||
P|40|0.01|10|1|1|0|40|1|1|1||1|*||0|0|0||||||||||||||||
*|A1|A1|A7|A16|F|F|F|F|F|F|F|||||||||||||||||||||||
*|||||kV|kV|kV|MW|MVAR|S|S||||||||||||||||||||||||
N|I|01|H01N01|H01N01|132|125.4|138.6|0|0|||||||||||||||||||||
N|I|01|H01N02|H01N02|20|19|21|0|0|||||||||||||||||||||||
N|I|01|H01N03|H01N03|20|19|21|0.42318823|0.204959433|||||||||||||||||||||
|||||||||||||||||
|||||||||||||||||
L|I|H010203|H01N02|H01N03|1.884|360|0.41071|0.207886957||3.19E-08|3.19E-08|||||||||||
L|I|H010304|H01N03|H01N04|1.62|360|0.35316|0.1787563||3.19E-08||3.19E-08||||||||||||
L|I|H010405|H01N04|H01N05|0.532|360|0.11598|0.058702686||3.19E-08||3.19E-08|||||||||||
L|I|H010506|H01N05|H01N06|1.284|360|0.27991|0.14168092||3.19E-08||3.19E-08||||||||||||
S|SH01|SEZIONE01|1|-3|+3|-100|+100|||||||||||||||||||
S|SH02|SEZIONE02|1|-3|+3|-100|+100|||||||||||||||||||
S|SH03|SEZIONE03|1|-3|+3|-100|+100|||||||||||||||||||
||||||||||||asasasas
S|SH04|SEZIONE04|1|-3|+3|-100|+100|||||||||||||||||||
*|comment
S|SH05|SEZIONE05|1|-3|+3|-100|+100|||||||||||||||||||
I'd like it to look like:
*|V|0|0|0|t|0|1|1|4|11|T4|H01||||||||||||||||||||||
*|comment
*|comment
P|40|0.01|10|1|1|0|40|1|1|1||1|*||0|0|0||||||||||||||||
*|A1|A1|A7|A16|F|F|F|F|F|F|F|||||||||||||||||||||||
*|||||kV|kV|kV|MW|MVAR|S|S||||||||||||||||||||||||
N|I|01|H01N01|H01N01|132|125.4|138.6|0|0|||||||||||||||||||||
N|I|01|H01N02|H01N02|20|19|21|0|0|||||||||||||||||||||||
N|I|01|H01N03|H01N03|20|19|21|0.42318823|0.204959433|||||||||||||||||||||
*|comment||||||||||||||||
*|comment|||||||||||||||||
L|I|H010203|H01N02|H01N03|1.884|360|0.41071|0.207886957||3.19E-08||3.19E-08|||||||||||
L|I|H010304|H01N03|H01N04|1.62|360|0.35316|0.1787563||3.19E-08||3.19E-08||||||||||||||
L|I|H010405|H01N04|H01N05|0.532|360|0.11598|0.058702686||3.19E-08||3.19E-08|||||||||||
L|I|H010506|H01N05|H01N06|1.284|360|0.27991|0.14168092||3.19E-08||3.19E-08||||||||||||
*|comment
*|comment
S|SH01|SEZIONE01|1|-3|+3|-100|+100|||||||||||||||||||
S|SH02|SEZIONE02|1|-3|+3|-100|+100|||||||||||||||||||
S|SH03|SEZIONE03|1|-3|+3|-100|+100|||||||||||||||||||
S|SH04|SEZIONE04|1|-3|+3|-100|+100|||||||||||||||||||
S|SH05|SEZIONE05|1|-3|+3|-100|+100|||||||||||||||||||
The data are divided into 'packages' distinct from the first letter (PNLS). Each package must have at least two dedicated lines (* |) which is then read as a comment. The white lines between different letters are filled with character * |. The lines between various letters that do not begin with * | to be added. The white lines and characters 'random' between identical letters are removed.
Perhaps it is clearer in the example files.
How do I manipulate the text? Thank you in advance for the help.
Use fileread to get your file into MATLAB.
text = fileread('my file to clean.txt');
Split the resulting character string up by splitting on the new lines. (The newlines characters depend on your operating system.)
lines = regexp(text, '\r\n', 'split');
It isn't entirely clear exactly how you want the file cleaned, but these things might get you started.
% Replace blank lines with comment string
blanks = cellfun(#isempty, lines);
comment = '*|comment';
lines(blanks) = cellstr(repmat(comment, sum(blanks), 1))
% Prepend comment string to lines that start with a pipe
lines = regexprep(lines, '^\|', '\*\|comment\|')
You'll be needing to know your way around regular expressions. There's a good guide to them at regular-expressions.info.