Optional Regex Component - python

I am using a regex function to return four OR 5 new fields: Store name, Details, Reason (optional), Pause time start, and Pause time end. Reason does not show up in every case like the other four fields. If it does show up, then it is between Store and Details within the text itself.
I am currently using this code to find the four required fields (which works):
parser = re.compile(r"your store, ([^,]+).*Details: ([^\n]*).*Created at: ([^\n]*).*Scheduled end time: ([^\n]*)", flags=re.DOTALL | re.MULTILINE)
df1['STORE']=''
df1['DETAILS']=''
df1['TIME_PAUSE_CREATED']=''
df1['TIME_PAUSE_END']=''
for index,i in enumerate(df1.DESCRIPTION):
txt = parser_reg.findall(i)
for field in txt:
df1['STORE'][index]=field[0]
df1['DETAILS'][index]=field[1]
df1['TIME_PAUSE_CREATED'][index]=field[2]
df1['TIME_PAUSE_END'][index]=field[3]
Is there a way to make an optional regex field and append that (else append 'Null') and continue scraping the other fields? I have tried using the following, but this only returns null values after store name:
parser = re.compile(r"your store, ([^,]+).*(Reason: ([^\n]*))?.*|Details: ([^\n]*).*)Created at: ([^\n]*).*Scheduled end time: ([^\n]*)", flags=re.DOTALL | re.MULTILINE)
Ideally I would be able to add the same respective column for 'Reason' like the other fields, but the regex expression still isn't working for me.
Thank you!

I take it from your example that Reason: is not always supplied? That's OK, just add it as an optional (one or zero occurrences) group. If it's not present, that capture group will be null. Between Store and Details add (?:Reason: (.*?))?. The final question mark says the whole Reason: section can occur zero or one times, making it optional. The whole regex (after a little extra cleanup) should read:
your store, ([^,]+).*?(?:Reason: (.*?))?\sDetails: (.*?)(?:\sDeactivation Time)?\sCreated at: (.*?[AP]M).*Scheduled end time: (.*?[AP]M)
Remember that Reason: will now be in field[1] and the other capture groups will be shifted down one.
I included this regex scanning your example string above from the Regex101 website.

Related

finding a regex to match and also trying to avoid using groups

Policy Id NPOH123414699 xyz OH 12605-12345 NASHVILLE TN 37101
Policy Id 9214234451
Policy Id AS12345FD ..... other info
I am trying to grab the number right after Id and only that and stop as soon as a space is encountered after the id. I don't know how to it.
my regex -->> "[P|p]olicy\s*[I|i]d\s*"
However it is capturing everything after Policy number and giving me this
NPOH123414699xyzOH1260512345NASHVILLETN37101
This is the regex without groups only full matches that u need to iterate (?<=Policy Id\s)\w+
here it is: https://regex101.com/r/8GEDs1/1
this simple pattern should be more than enough if you insist to use regex
a = re.findall(r"Id\s([0-9A-Z]+)", "Policy Id B1231232131 xysa da")[0]
You can:
(?<=\bPolicy Id\s)(\w+)
Reference:
https://regex101.com/r/LrzDX5/1

How to extract string between numbers? (And keep first number in the string?)

I am trying to extract data from a change log using RegEx. Here is an example how the change log is structured:
96545
this is some changes in the ticket
some new version: x.x.22
another change
new version: x.y.2.2
120091
this is some changes in the ticket
some new version: z.z.22
another change
another change
another change
new version: z.y.2.2
120092
...
...
...
Each data point starts with an ID which has a range of 5 to 6 digits.
Moreover there is a variable amount of changes (lines) in the log per ID.
Each data point ends with new version: ***. *** is string which is variable for every ID.
I was using the RegExStrom Tester to test my RegEx.
So far I have: ^\w{5,6}(.|\n)*?\d{5,6} however the result includes the ID from the next ticket, which I need to avoid.
Result:
96545
this is some changes in the ticket
some new version: x.x.22
another change
new version: x.y.2.2
120091
Expected Result:
96545
this is some changes in the ticket
some new version: x.x.22
another change
new version: x.y.2.2
Captures each records ID in group 1 and content in group 2
r'(?ms)^(\d{5,6}\r?\n)(.*?)^new version:'
https://regex101.com/r/A3ejjN/1
If the problem was that you capture the ID of the next Ticket just use positive look ahead to mach it but not capture it, or consume it:
# end of tickets is the end of line that the line after it contains the Id of the next ticket
pattern = r"\d{5,6}[\s\S]*?(?=\n\d{5,6})"
# to extract first ticket info just use search
print(re.search(pattern, text).group(0))
# to extract all tickets info in a list use findall
print(re.findall(pattern, text))
# if the file is to big and you want to extract tickets in lazy mode
for ticket in re.finditer(pattern,text):
print(ticket.group(0))
This would do it:
^\d{5,6}[\r\n]*.*?^new version:[^\r\n]*
Just make sure to enable the MULTILINE and DOTALL flags via re.MULTILINE | re.DOTALL
https://regex101.com/r/YeIUQx/1
Your regular expression is close. Its issue is that it's "ending" at the start of the next log, by using \d{5,6} to mark the end of a log entry (and matching it in the process). As Wiktor mentioned, it would make more sense to use "new version" as the delimeter, so I've done that here.
found_matches = re.findall("(^\d{5,6}[\s\S]*?^new version: .*$)", log_file_content, re.MULTILINE)
The regex (^\d{5,6}[\s\S]*?^new version: .*$) searches for 5 or 6 digits at the start of the line, and then takes any character (including newlines) up until the first instance of new version: that appears at the start of a line. It then reads to the end of the line to finish that group. Since you're going to be matching across newlines, be sure to remember the re.MULTILINE argument!
Test the regex here, and the full python code here.

Is there an R or Python function for separating information in non-delimited strings, where the information varies?

I am currently cleaning up a messy data sheet in which information is given in one excel cell where the different characteristics are not delimited (no comma, spaces are random).
Thus, my problem is to separate the different information without a delimitation I could use in my code (can't use a split command)
I assume that I need to include some characteristics of each part of information, such that the corresponding characteristic is recognized. However, I don't have a clue how to do that since I am quite new to Python and I only worked with R in the framework of regression models and other statistical analysis.
Short data example:
INPUT:
"WMIN CBOND12/05/2022 23554132121"
or
"WalMaInCBND 12/05/2022-23554132121"
or
"WalmartI CorpBond12/05/2022|23554132121"
EXPECTED OUTPUT:
"Walmart Inc.", "Corporate Bond", "12/05/2022", "23554132121"
So each of the "x" should be classified in a new column with the corresponding header (Company, Security, Maturity, Account Number)
As you can see the input varies randomly but I want to have the same output for each of the three inputs given above (I have over 200k data points with different companies, securities etc.)
First Problem is how to separate the information effectively without being able to use a systematic pattern.
Second Problem (lower priority) is how to identify the company without setting up a dictionary with 50 different inputs for 50k companies.
Thanks for your help!
I recommend to first introduce useful seperators where possible and construct a dictionary of replacements for processing with regular expressions.
import re
s = 'WMIN CBOND12/05/2022 23554132121'
# CAREFUL this not a real date regex, this should just
# illustrate the principle of regex
# see https://stackoverflow.com/a/15504877/5665958 for
# a good US date regex
date_re = re.compile('([0-9]{2}/[0-9]{2}/[0-9]{4})')
# prepend a whitespace before the date
# this is achieved by searching the date within the string
# and replacing it with itself with a prepended whitespace
# /1 means "insert the first capture group", which in our
# case is the date
s = re.sub(date_re, r' \1', s)
# split by one or more whitespaces and insert
# a seperator (';') to make working with the string
# easier
s = ';'.join(s.split())
# build a dictionary of replacements
replacements = {
'WMIN': 'Walmart Inc.',
'CBOND': 'Corporate Bond',
}
# for each replacement apply subsitution
# a better, but more replicated solution for
# this is given here:
# https://stackoverflow.com/a/15175239/5665958
for pattern, r in replacements.items():
s = re.sub(pattern, r, s)
# use our custom separator to split the parts
out = s.split(';')
print(out)
Using python and regular expressions:
import re
def make_filter(pattern):
pattern = re.compile(pattern)
def filter(s):
filtered = pattern.match(s)
return filtered.group(1), filtered.group(2), filtered.group(3), filtered.group(4)
return filter
filter = make_filter("^([a-zA-Z]+)\s([a-zA-Z]+)(\d+/\d+/\d+)\s(\d+)$")
filter("WMIN CBOND12/05/2022 23554132121")
The make_filter function is just an utility to allow you to modify the pattern. It returns a function that will filter the output according to that pattern. I use it with the "^([a-zA-Z]+)\s([a-zA-Z]+)(\d+/\d+/\d+)\s(\d+)$" pattern that considers some text, an space, some text, a date, an space, and a number. If you want to kodify this pattern provide more info about it. The output will be ("WMIN", "CBOND", "12/05/2022", "23554132121").
welcome! Yeah, we would definitely need to see more examples and regex seems to be the way to go... but since there seems to be no structure, I think it's better to think of this as seperate steps.
We KNOW there's a date which is (X)X/(X)X/XXXX (ie. one or two digit day, one or two digit month, four digit year, maybe with or without the slashes, right?) and after that there's numbers. So solve that part first, leaving only the first two categories. That's actually the easy part :) but don't lose heart!
if these two categories might not have ANY delimiter (for example WMINCBOND 12/05/202223554132121, or delimiters are not always delimiters for example IMAGINARY COMPANY X CBOND, then you're in deep trouble. :) BUT this is what we can do:
Gather a list of all the codes (hopefully you have that).
use str_detect() on each code and see if you can recognize the exact string in any of the dataset (if you do have the codes lemme know I'll write the code to do this part).
What's left after identifying the code will be the CBOND, whatever that is... so do that part last... what's left of the string will be that. Alternatively, you can use the same str_detect() if you have a list of whatever CBOND stuff is.
ONLY AFTER YOU'VE IDENTIFIED EVERYTHING, you can then replace the codes for what they stand for.
If you have the code-list let me know and I'll post the code.
edit
s = c("WMIN CBOND12/05/2022 23554132121",
"WalMaInCBND 12/05/2022-23554132121",
"WalmartI CorpBond12/05/2022|23554132121")
ID = gsub("([a-zA-Z]+).*","\\1",s)
ID2 = gsub(".* ([a-zA-Z]+).*","\\1",s)
date = gsub("[a-zA-Z ]+(\\d+\\/\\d+\\/\\d+).*","\\1",s)
num = gsub("^.*[^0-9](.*$)","\\1",s)
data.frame(ID=ID,ID2=ID2,date=date,num=num,stringsAsFactors=FALSE)
ID ID2 date num
1 WMIN CBOND 12/05/2022 23554132121
2 WalMaInCBND WalMaInCBND 12/05/2022-23554132121 12/05/2022 23554132121
3 WalmartI CorpBond 12/05/2022 23554132121
Works for cases 1 and 3 but I haven't figured out a logic for the second case, how can we know where to split the string containing the company and security if they are not separated?

Substring with multiple instances of the same character

So I am using a Magtek USB reader that will read card information,
As of right now I can swipe a card and I get a long string of information that goes into a Tkinter Entry textbox that looks like this
%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?
All of the data has been randomized, but that's the format
I've got a tkinter button (it gets the text from the entry box in the format I included above and runs this)
def printCD(self):
print(self.carddata.get())
self.card_data_get = self.carddata.get()
self.creditnumber =
self.card_data_get[self.card_data_get.find("B")+1:
self.card_data_get.find("^")]
print(self.creditnumber)
print(self.card_data_get.count("^"))
This outputs:
%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?
8954756016548963
This yields no issues, but if I wanted to get the next two variables firstname, and lastname
I would need to reuse self.variable.find("^") because in the format it's used before LAST and after INITIAL
So far when I've tried to do this it hasn't been able to reuse "^"
Any takers on how I can split that string of text up into individual variables:
Card Number
First Name
Last Name
Expiration Date
Regex will work for this. I didn't capture everything because you didn't detail what's what but here's an example of capturing the name:
import re
data = "%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?"
matches = re.search(r"\^(?P<name>.+)\^", data)
print(matches.group('name'))
# LAST/FIRST INITIAL
If you aren't familiar with regex, here's a way of testing pattern matching: https://regex101.com/r/lAARCP/1 and an intro tutorial: https://regexone.com/
But basically, I'm searching for (one or more of anything with .+ between two carrots, ^).
Actually, since you mentioned having first and last separate, you'd use this regex:
\^(?P<last>.+)/(?P<first>.+)\^
This question may also interest you regarding finding something twice: Finding multiple occurrences of a string within a string in Python
If you find regex difficult you can divide the problem into smaller pieces and attack one at a time:
data = '%B8954756016548963^LAST/FIRST INITIAL^180912345678912345678901234?;8954756016548963=180912345678912345678901234?'
pieces = data.split('^') # Divide in pieces, one of which contains name
for piece in pieces:
if '/' in piece:
last, the_rest = piece.split('/')
first, initial = the_rest.split()
print('Name:', first, initial, last)
elif piece.startswith('%B'):
print('Card no:', piece[2:])

Irregular String Parsing on Python

I'm new to python/django and I am trying to suss out more effective information from my scraper. Currently, the scraper takes a list of comic book titles and correctly divides them into a CSV list in three parts (Published Date, Original Date, and Title). I then pass the current date and title through to different parts of my databse, which I do in my Loader script (convert mm/dd/yy into yyyy-mm-dd, save to "pub_date" column, title goes to "title" column).
A common string can look like this:
10/12/11|10/12/11|Stan Lee's Traveler #12 (10 Copy Incentive Cover)
I am successfully grabbing the date, but the title is trickier. In this instance, I'd ideally like to fill three different columns with the information after the second "|". The Title should go to "title", a charfield. the number 12 (after the '#') should go into the DecimalField "issue_num", and everything between the '()' 's should go into the "Special" charfield. I am not sure how to do this kind of rigorous parsing.
Sometimes, there are multiple #'s (one comic in particular is described as a bundle, "Containing issues #90-#95") and several have multiple '()' groups (such as, "Betrayal Of The Planet Of The Apes #1 (Of 4)(25 Copy Incentive Cover)
)
What would be a good road to start onto crack this problem? My knowledge of If/else statements quickly fell apart for the more complicated lines. How can I efficiently and (if possible) pythonic-ly parse through these lines and subdivide them so I can later slot them into the correct place in my database?
Use the regular expression module re. For example, if you have the third |-delimited field of your sample record in a variable s, then you can do
match = re.match(r"^(?P<title>[^#]*) #(?P<num>[0-9]+) \((?P<special>.*)\)$", s)
title = match.groups('title')
issue = match.groups('num')
special = match.groups('special')
You'll get an IndexError in the last three lines for a missing field. Adapt the RE until it parses everything your want.
Parsing the title is the hard part, it sounds like you can handle the dates etc yourself. The problem is that there is not one rule that can parse every title but there are many rules and you can only guess which one works on a particular title.
I usually handle this by creating a list of rules, from most specific to general and try them out one by one until one matches.
To write such rules you can use the re module or even pyparsing.
The general idea goes like this:
class CantParse(Exception):
pass
# one rule to parse one kind of title
import re
def title_with_special( title ):
""" accepts only a title of the form
<text> #<issue> (<special>) """
m = re.match(r"[^#]*#(\d+) \(([^)]+)\)", title)
if m:
return m.group(1), m.group(2)
else:
raise CantParse(title)
def parse_extra(title, rules):
""" tries to parse extra information from a title using the rules """
for rule in rules:
try:
return rule(title)
except CantParse:
pass
# nothing matched
raise CantParse(title)
# lets try this out
rules = [title_with_special] # list of rules to apply, add more functions here
titles = ["Stan Lee's Traveler #12 (10 Copy Incentive Cover)",
"Betrayal Of The Planet Of The Apes #1 (Of 4)(25 Copy Incentive Cover) )"]
for title in titles:
try:
issue, special = parse_extra(title, rules)
print "Parsed", title, "to issue=%s special='%s'" % (issue, special)
except CantParse:
print "No matching rule for", title
As you can see the first title is parsed correctly, but not the 2nd. You'll have to write a bunch of rules that account for every possible title format in your data.
Regular expression is the way to go. But if you fill uncomfortably writing them, you can try a small parser that I wrote (https://github.com/hgrecco/stringparser). It translates a string format (PEP 3101) to a regular expression. In your case, you will do the following:
>>> from stringparser import Parser
>>> p = Parser(r"{date:s}\|{date2:s}\|{title:s}#{issue:d} \({special:s}\)")
>>> x = p("10/12/11|10/12/11|Stan Lee's Traveler #12 (10 Copy Incentive Cover)")
OrderedDict([('date', '10/12/11'), ('date2', '10/12/11'), ('title', "Stan Lee's Traveler "), ('issue', 12), ('special', '10 Copy Incentive Cover')])
>>> x.issue
12
The output in this case is an (ordered) dictionary. This will work for any simple cases and you might tweak it to catch multiple issues or multiple ()
One more thing: notice that in the current version you need to manually escape regex characters (i.e. if you want to find |, you need to type \|). I am planning to change this soon.

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