Regex multiple occurrences of same character Python - python

I'm having a problem with isolating a dynamic string+int occurrence in a text:
I want to capture "k9034", the first char is always a string, the length of the following int can vary in length "9034...76"
Given:
K:\dir1\executions\ is static and always the same
the number of \ is always the same in the full text
So far I have made a script:
^K.*executions\\([a-t])
It captures K:\dir1\executions\ in match 1 and k in group 1
Since k9034 varies in length I would like to write something like:
^K.*executions\\([a-t].*)\\.*
For "\." I would like to capture the first \ after k9034 and put it in a match or other group(\.), but with my script it captures the wrong \
Im using regex101.com to test it.
K:\dir1\executions\k9034\kejlk34f\fdshf3\
Best regards
H

You could write it either using 2 capture groups:
^K:\\[^\s\\]+\\executions(\\[a-t]\d+)(\\)
Regex demo
Or use a single capture group
^K:\\[^\s\\]+\\executions(\\[a-t]\d+\\)
Explanation
^ Start of string
K:\\ Match K:\
[^\s\\]+ Match 1+ chars other than \ or whitespace chars
\\executions Match \executions
(\\[a-t]\d+\\) Capture group 1, match \ then a single char in the range a-t and 1+ digits
Regex demo

Related

Matching consecutive digits in regex while ignoring dashes in python3 re

I'm working to advance my regex skills in python, and I've come across an interesting problem. Let's say that I'm trying to match valid credit card numbers , and on of the requirments is that it cannon have 4 or more consecutive digits. 1234-5678-9101-1213 is fine, but 1233-3345-6789-1011 is not. I currently have a regex that works for when I don't have dashes, but I want it to work in both cases, or at least in a way i can use the | to have it match on either one. Here is what I have for consecutive digits so far:
validNoConsecutive = re.compile(r'(?!([0-9])\1{4,})')
I know I could do some sort of replace '-' with '', but in an effort to make my code more versatile, it would be easier as just a regex. Here is the function for more context:
def isValid(number):
validStart = re.compile(r'^[456]') # Starts with 4, 5, or 6
validLength = re.compile(r'^[0-9]{16}$|^[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{4}$') # is 16 digits long
validOnlyDigits = re.compile(r'^[0-9-]*$') # only digits or dashes
validNoConsecutive = re.compile(r'(?!([0-9])\1{4,})') # no consecutives over 3
validators = [validStart, validLength, validOnlyDigits, validNoConsecutive]
return all([val.search(number) for val in validators])
list(map(print, ['Valid' if isValid(num) else 'Invalid' for num in arr]))
I looked into excluding chars and lookahead/lookbehind methods, but I can't seem to figure it out. Is there some way to perhaps ignore a character for a given regex? Thanks for the help!
You can add the (?!.*(\d)(?:-*\1){3}) negative lookahead after ^ (start of string) to add the restriction.
The ^(?!.*(\d)(?:-*\1){3}) pattern matches
^ - start of string
(?!.*(\d)(?:-*\1){3}) - a negative lookahead that fails the match if, immediately to the right of the current location, there is
.* - any zero or more chars other than line break chars as many as possible
(\d) - Group 1: one digit
(?:-*\1){3} - three occurrences of zero or more - chars followed with the same digit as captured in Group 1 (as \1 is an inline backreference to Group 1 value).
See the regex demo.
If you want to combine this pattern with others, just put the lookahead right after ^ (and in case you have other patterns before with capturing groups, you will need to adjust the \1 backreference). E.g. combining it with your second regex, validLength = re.compile(r'^[0-9]{16}$|^[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{4}$'), it will look like
validLength = re.compile(r'^(?!.*(\d)(?:-*\1){3})(?:[0-9]{16}|[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{4})$')

Not able get desired output after string parsing through regex

input =
6:/BENM/Gravity Exports/REM//INV: 3267/FEB20:65:ghgh
6:/BENM/Tabuler Trading/REM//IMP/2020-341
original_regex = 6:[A-Za-z0-9 \/\.\-:] - bt this is taking full string 6:/BENM/Gravity Exports/REM//INV: 3267/FEB20:65:ghgh
modified_regex_pattern = 6:[A-Za-z0-9 \/\.\-:]{1,}[\/-:]
In the first string i want output till
6:/BENM/Gravity Exports/REM//INV: 3267/FEB20
but its giving till :65:
Can anyone suggest better way to write this.
Example as below
https://regex101.com/r/pAduvy/1
You could for example use a capturing group with an optional part at the end to match the :digits:a-z part.
(6:[A-Za-z0-9 \/.:-]+?)(?::\d+:[a-z]+)?$
( Capture group 1
6:[A-Za-z0-9 \/.:-]+? Match any of the listed in the character class as least as possible
) Close group 1
(?::\d+:[a-z]+)? optionally match the part at the end that you don't want to include
$ End of string
Regex demo
Note Not sure if intended, but the last part of your pattern [\/-:] denotes a range from ASCII range 47 - 58.
Or a more precise pattern to get the match only
6:/\w+/\w+ \w+/[A-Z]+//[A-Z]+(?:: \d+)?/[A-Z]*\d+(?:-\d+)?
6:/\w+/\w+ Match 6 and 2 times / followed by 1+ word chars and a space
\w+/[A-Z]+//[A-Z]+ Match 1+ word chars, / and uppercase chars, // and again uppercase chars
(?:: \d+)? Optionally match a space and 1+ digits
/[A-Z]*\d+ Match /, optional uppercase chars and 1+ digits
(?:-\d+)? Optionally match - and 1+ digits
Regex demo

Fetching respective group values in a regex expression

I have an example string like below:
Handling - Uncrating of 3 crates - USD600 each 7%=126.00 1,800.00
I can have another example string that can be like:
Unpacking/Unremoval fee Zero Rated 100.00
I am trying to access the first set of words and the last number values.
So I want the dict to be
{'Handling - Uncrating of 3 crates - USD600 each':1800.00}
or
{'Unpacking/Unremoval fee':100.00}
There might be strings where none of the above patterns (Zero Rated or something with %) present and I would skip those strings.
To do that, I was regexing the following pattern
pattern = re.search(r'(.*)Zero.*Rated\s*(\S*)',line.strip())
and then
pattern.group(1)
gives the keys for dict and
pattern.group(2)
gives the value of 1800.00. This works for lines where Zero Rated is present.
However if I want to also check for pattern where Zero Rated is not present but % is present as in first example above, I was trying to use | but it didn't work.
pattern = re.search(r'(.*)Zero.*Rated|%\s*(\S*)',line.strip())
But this time I am not getting the right pattern groups as it is fetching groups.
Sites like regex101.com can help debug regexes.
In this case, the problem is with operator precedence; the | operates over the whole of the rest of the regex. You can group parts of the regex without creating additional groups with (?: )
Try: r'(.*)(?:Zero.*Rated|%)\s*(\S*)'
Definitely give regex101.com a go, though, it'll show you what's going on in the regex.
You might use
^(.+?)\s*(?:Zero Rated|\d+%=\d{1,3}(?:\,\d{3})*\.\d{2})\s*(\d{1,3}(?:,\d{3})*\.\d{2})
The pattern matches
^ Start of string
(.+?) Capture group 1, match any char except a newline as least as possible
\s* Match 0+ whitespace chars
(?: Non capture group
Zero Rated Match literally
| Or
\d+%= Match 1+ digits and %=
\d{1,3}(?:\,\d{3})*\.\d{2} Match a digit format of 1-3 digits, optionally repeated by a comma and 3 digits followed by a dot and 2 digits
) Close non capture group
\s* Match 0+ whitespace chars
(\d{1,3}(?:,\d{3})*\.\d{2}) Capture group 2, match the digit format
Regex demo | Python demo
For example
import re
regex = r"^(.+?)\s*(?:Zero Rated|\d+%=\d{1,3}(?:\,\d{3})*\.\d{2})\s*(\d{1,3}(?:,\d{3})*\.\d{2})"
test_str = ("Handling - Uncrating of 3 crates - USD600 each 7%=126.00 1,800.00\n"
"Unpacking/Unremoval fee Zero Rated 100.00\n"
"Delivery Cartage - IT Equipment, up to 1000kgs - 7%=210.00 3,000.00")
print(dict(re.findall(regex, test_str, re.MULTILINE)))
Output
{'Handling - Uncrating of 3 crates - USD600 each': '1,800.00', 'Unpacking/Unremoval fee': '100.00', 'Delivery Cartage - IT Equipment, up to 1000kgs -': '3,000.00'}

Key error when using regex quantifier python

I am trying to capture words following specified stocks in a pandas df. I have several stocks in the format $IBM and am setting a python regex pattern to search each tweet for 3-5 words following the stock if found.
My df called stock_news looks as such:
Word Count
0 $IBM 10
1 $GOOGL 8
etc
pattern = ''
for word in stock_news.Word:
pattern += '{} (\w+\s*\S*){3,5}|'.format(re.escape(word))
However my understanding is that {} should be a quantifier, in my case matching between 3 to 5 times however I receive the following KeyError:
KeyError: '3,5'
I have also tried using rawstrings with r'{} (\w+\s*\S*){3,5}|' but to no avail. I also tried using this pattern on regex101 and it seems to work there but not in my Pycharm IDE. Any help would be appreciated.
Code for finding:
pat = re.compile(pattern, re.I)
for i in tweet_df.Tweets:
for x in pat.findall(i):
print(x)
When you build your pattern, there is an empty alternative left at the end, so your pattern effectively matches any string, every empty space before non-matching texts.
You need to build the pattern like
(?:\$IBM|\$GOOGLE)\s+(\w+(?:\s+\S+){3,5})
You may use
pattern = r'(?:{})\s+(\w+(?:\s+\S+){{3,5}})'.format(
"|".join(map(re.escape, stock_news['Word'])))
Mind that the literal curly braces inside an f-string or a format string must be doubled.
Regex details
(?:\$IBM|\$GOOGLE) - a non-capturing group matching either $IBM or $GOOGLE
\s+ - 1+ whitespaces
(\w+(?:\s+\S+){3,5}) - Capturing group 1 (when using str.findall, only this part will be returned):
\w+ - 1+ word chars
(?:\s+\S+){3,5} - a non-capturing* group matching three, four or five occurrences of 1+ whitespaces followed with 1+ non-whitespace characters
Note that non-capturing groups are meant to group some patterns, or quantify them, without actually allocating any memory buffer for the values they match, so that you could capture only what you need to return/keep.

RegEx for matching two digits and everything except new lines and dot

Using python v3, I'm trying to find a string only if it contains one to two digits (and not anymore than that in the same number) along with everything else following it. The match breaks on periods or new lines.
\d{1,2}[^.\n]+ is almost right except it returns numbers greater than two digits.
For example:
"5+years {} experience. stop.
10 asdasdas . 255
1abc1
5555afasfasf++++s()(jn."
Should return:
5+years {} experience
10 asdasdas
1abc1
Based upon your description and your sample data, you can use following regex to match the intended strings and discard others,
^\d[^\d.]*\d?[^\d.\n]*(?=\.|$)
Regex Explanation:
^ - Start of line
\d - Matches a digit
[^\d.]* - This matches any character other than digit or dot zero or more times. This basically allows optionally matching of non-digit non-dot characters.
\d? - As you want to allow one or two digits, this is the second digit which is optional hence \d followed by ?
[^\d.\n]* - This matches any character other than digit or dot or newline
(?=\.|$) - This positive look ahead ensures, the match either ends with a dot or end of line
Also, notice, multiline mode is enabled as ^ and $ need to match start of line and end of line.ad
Regex Demo 1
Code:
import re
s = '''5+years {} experience. stop.
10 asdasdas . 255
1abc1
5555afasfasf++++s()(2jn.'''
print(re.findall(r'(?m)^\d[^\d.]*\d?[^\d.\n]*(?=\.|$)', s))
Prints:
['5+years {} experience', '10 asdasdas ', '1abc1']
Also, if matching lines doesn't necessarily start with digits, you can use this regex to capture your intended string but here you need to get your string from group1 if you want captured string to start with number only, and if intended string doesn't necessarily have to start with digits, then you can capture whole match.
^[^\d\n]*(\d[^\d.]*\d?[^\d.\n]*)(?=\.|$)
Regex Explanation:
^ - Start of line
[^\d\n]* - Allows zero or more non-digit characters before first digit
( - Starts first grouping pattern to capture the string starting with first digit
\d - Matches a digit
[^\d.]* - This matches any character other than digit or dot zero or more times. This basically allows optionally matching of non-digit non-dot characters.
\d? - As you want to allow one or two digits, this is the second digit which is optional hence \d followed by ?
[^\d.\n]* - This matches any character other than digit or dot or newline
`) - End of first capturing pattern
(?=\.|$) - This positive look ahead ensures, the match either ends with a dot or end of line
Multiline mode is enabled which you can enable by placing (?m) before start of regex also called inline modifier or by passing third argument to re.search as re.MULTILINE
Regex Demo 2
Code:
import re
s = '''5+years {} experience. stop.
10 asdasdas . 255
1abc1
aaa1abc1
aa2aa1abc1
5555afasfasf++++s()(2jn.'''
print(re.findall(r'(?m)^[^\d\n]*(\d[^\d.]*\d?[^\d.\n]*)(?=\.|$)', s))
Prints:
['5+years {} experience', '10 asdasdas ', '1abc1', '1abc1']

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