Avoid literal repetition - regex

Suppose I have this string:
Address XXXXX city XXXXX
And this regEX:
Address (.*?) city (.*?)
What will happen if the Address is "The city of London" ?


It depends on whether your reex engine is in greedy mode or not.
If it's in greedy mode, it will work as expected since it will look for the longest match.
Whether your particular regex engines runs in greedy mode by default, or whether it even has a greedy mode, is not something we can tell you based on the information provided in the question.
If you're using .NET, this page has a description on greedy versus lazy matching.
Basically, given the string XYZZY, the regex X.*Y will match XYZZY (greedy) while X.*?Y will match XY (lazy).
What you need is a way to ensure you can differentiate between the delimiters and the elements of your string, otherwise you'll be in trouble no matter what, such as with:
Address The city baths city Manchester city, England
Perhaps you could look into something like:
Address "put address here" city "put city here"
and try to make sure you never get a city name with quotes in it. However, be careful. I once worked on a project where we managed to get some decent compression on city names (it was embedded so every byte counted) by only having to store alpha characters.
Shortly thereafter, we rolled out nationally and the residents of A1 mining settlement were rather miffed at our short-sightedness :-) One town in the whole of Oz with a digit in the name, who'd have thought?
Alternatively, put the address and city on separate lines thus:
Address: The city baths
City: Manchester city, England
Then you can look for things like:
^Address:\s*(.*)$
^City:\s*(.*)$

Related

How can a regex catch all parts before a keyword from a finite set, but sometimes separated only by a single space

This question relates to PCRE regular expressions.
Part of my big dataset are address data like this:
12H MARKET ST. Canada
123 SW 4TH Street USA
ONE HOUSE USA
1234 Quantity Dr USA
123 Quality Court Canada
1234 W HWY 56A USA
12345 BERNARDO CNTR DRIVE Canada
12 VILLAGE PLAZA USA
1234 WEST SAND LAKE RD ?567 USA
1234 TELEGRAM BLVD SUITE D USA
1234-A SOUTHWEST FRWY USA
123 CHURCH STREET USA
123 S WASHINGTON USA
123 NW-SE BLVD USA
# USA
1234 E MAIN STREET USA
I would like to extract the street names including house numbers and additional information from these records. (Of course there are other things in those records and I already know how to extract them).
For the purpose of this question I just manually clipped the interesting part from the data for this example.
The number of words in the address parts is not known before. The only criterion I have found so far is to find the occurrence of country names belonging to some finite set, which of course is bigger than (USA|Canada). For brevity I limit my example just to those two countries.
This regular expression
([a-zA-Z0-9?\-#.]+\s)
already isolates the words making up what I am after, including one space after them. Unfortunately there are cases, where the country after the to-be-extracted street information is only separated by a single space from the country, like e.g. in the first and in the last example.
Since I want to capture the matching parts glued together, I place a + sign behind my regular expression:
([a-zA-Z0-9?\-#.]+\s)+
but then in the two nasty cases with only one separating space before the country, the country is also caught!
Since I know the possible countries from looking at the data, I could try to exclude them by a look ahead-condition like this:
([a-zA-Z0-9?\-#.]+\s)(?!USA|Canada)
which excludes ST. from the match in the first line and STREET from the match in the last line. Of course the single capture groups are not yet glued together by this.
So I would add a plus sign to the group on the left:
([a-zA-Z0-9?\-#.]+\s)+(?!USA|Canada)
But then ST. and STREET and the Country, separated by only a single space, are caught again together with the country, which I want to exclude from my result!
How would you proceed in such a case?
If it would be possible by properly using regular expressions to replace each country name by the same one preceded by an additional space (or even to do this only for cases, where there is only a single space in front of one of the country-names), my problem would be solved. But I want to avoid such a substitution for the whole database in a separate run because a country name might appear in some other column too.
I am quite new to regular expressions and I have no idea how to do two processing steps onto the same input in sequence. - But maybe, someone has a better idea how to cope with this problem.

If I understand correctly, you want all content before the country (excluding spaces before the country). The country will always be present at the end of the line and comes from a list.
So you should be able to set the 'global' and 'multiline' options and then use the following regex:
^(.*?)(?=\s+(USA|Canada)\s*$)
Explanation:
^(.*) match all characters from start of line
(?=\s+(USA|Canada)\s*$) look ahead for one or more spaces, followed by one of the country names, followed by zero or more spaces and end of line.
That should give you a list with all addresses.
Edit:
I have changed the first part to: (.*?), making it non-greedy. That way the match will stop at the last letter before country instead of including some spaces.

Using regex and vba, extracting parts of data

I have an excel spreadsheet and within its contents it is formatted like -
Street Name, Street Number Street Direction(may not be present represented be an NSWE)
So it could look like John Doe Ave, 900 E or Jane Doe DR, 100
However, the people who used this spreadsheet put business names or other information that shouldn't be present
The part I'm stuck at is using regex patterns I'm not familiar with it and it confuses me
I have this variable
Dim strPattern As String: strPattern = "^(.+),\s(\d+)\s([NWSEnwse])"
So, I have this its working SLIGHTLY I wanted to know what changes I could make to this so it would include or exlude NWSEnwse, because right now it detects the address only when street direction is present

You may use this regex pattern to match it.
^(.+),\s+(\d+)(\s+[NWSEnwse])?
The ? at the end signifies that that part is optional.
I also replaced \s with \s+ to account for any extra spaces that might have crept in.

Regex parse with alteryx

One of the columns has the data as below and I only need the suburb name, not the state or postcode.
I'm using Alteryx and tried regex (\<\w+\>)\s\<\w+\> but only get a few records to the new column.
Input:
CABRAMATTA
CANLEY HEIGHTS
ST JOHNS PARK
Parramatta NSW 2150
Claymore 2559
CASULA
Output
CABRAMATTA
CANLEY HEIGHTS
ST JOHNS PARK
Parramatta
Claymore
CASULA

This regex matches all letter-words up to but not including an Australian state abbreviation (since the addresses are clearly Australian):
( ?(?!(VIC|NSW|QLD|TAS|SA|WA|ACT|NT)\b)\b[a-zA-Z]+)+
See demo
The negative look ahead includes a word boundary to allow suburbs that start with a state abbreviation (see demo).

Expanding on Bohemian's answer, you can use groupings to do a REGEXP REPLACE in alteryx. So:
REGEX_Replace([Field1], "(.*)(\VIC|NSW|QLD|TAS|SA|WA|ACT|NT)+(\s*\d+)" , "\1")
This will grab anything that matches in the first group (so just the suburb). The second and third groups match the state and the zip. Not a perfect regex, but should get you most of the way there.

I think this workflow will help you :

Regular expression for address field validation

I am trying to write a regular expression that facilitates an address, example 21-big walk way or 21 St.Elizabeth's drive I came up with the following regular expression but I am not too keen to how to incorporate all the characters (alphanumeric, space dash, full stop, apostrophe)
"regexp=^[A-Za-z-0-99999999'

See the answer to this question on address validating with regex:
regex street address match
The problem is, street addresses vary so much in formatting that it's hard to code against them. If you are trying to validate addresses, finding if one isn't valid based on its format is mighty hard to do.
This would return the following address (253 N. Cherry St. ), anything with its same format:
\d{1,5}\s\w.\s(\b\w*\b\s){1,2}\w*\.
This allows 1-5 digits for the house number, a space, a character followed by a period (for N. or S.), 1-2 words for the street name, finished with an abbreviation (like st. or rd.).
Because regex is used to see if things meet a standard or protocol (which you define), you probably wouldn't want to allow for the addresses provided above, especially the first one with the dash, since they aren't very standard. you can modify my above code to allow for them if you wish--you could add
(-?)
to allow for a dash but not require one.
In addition, http://rubular.com/ is a quick and interactive way to learn regex. Try it out with the addresses above.

In case if you don't have a fixed format for the address as mentioned above, I would use regex expression just to eliminate the symbols which are not used in the address (like specialized sybmols - &(%#$^). Result would be:
[A-Za-z0-9'\.\-\s\,]

Just to add to Serzas' answer(since don't have enough reps. to comment).
alphabets and numbers can effectively be replaced by \w for words.
Additionally apostrophe,comma,period and hyphen doesn't necessarily need a backslash.
My requirement also involved front and back slashes so \/ and finally whitespaces with \s. The working regex for me ,as such was :
pattern: "[\w',-\\/.\s]"

Regular expression for simple address validation
^[#.0-9a-zA-Z\s,-]+$
E.g. for Address match case
#1, North Street, Chennai - 11
E.g. for Address not match case
$1, North Street, Chennai # 11

I have succesfully used ;
Dim regexString = New stringbuilder
With regexString
.Append("(?<h>^[\d]+[ ])(?<s>.+$)|") 'find the 2013 1st ambonstreet
.Append("(?<s>^.*?)(?<h>[ ][\d]+[ ])(?<e>[\D]+$)|") 'find the 1-7-4 Dual Ampstreet 130 A
.Append("(?<s>^[\D]+[ ])(?<h>[\d]+)(?<e>.*?$)|") 'find the Terheydenlaan 320 B3
.Append("(?<s>^.*?)(?<h>\d*?$)") 'find the 245e oosterkade 9
End With
Dim Address As Match = Regex.Match(DataRow("customerAddressLine1"), regexString.ToString(), RegexOptions.Multiline)
If Not String.IsNullOrEmpty(Address.Groups("s").Value) Then StreetName = Address.Groups("s").Value
If Not String.IsNullOrEmpty(Address.Groups("h").Value) Then HouseNumber = Address.Groups("h").Value
If Not String.IsNullOrEmpty(Address.Groups("e").Value) Then Extension = Address.Groups("e").Value
The regex will attempt to find a result, if there is none, it move to the next alternative. If no result is found, none of the 4 formats where present.

This one worked for me:
\d+[ ](?:[A-Za-z0-9.-]+[ ]?)+(?:Avenue|Lane|Road|Boulevard|Drive|Street|Ave|Dr|Rd|Blvd|Ln|St)\.?
The source: https://www.codeproject.com/Tips/989012/Validate-and-Find-Addresses-with-RegEx

Regex is a very bad choice for this kind of task. Try to find a web service or an address database or a product which can clean address data instead.
Related:
Address validation using Google Maps API

As a simple one line expression recommend this,
^([a-zA-z0-9/\\''(),-\s]{2,255})$

I needed
STREET # | STREET | CITY | STATE | ZIP
So I wrote the following regex
[0-9]{1,5}( [a-zA-Z.]*){1,4},?( [a-zA-Z]*){1,3},? [a-zA-Z]{2},? [0-9]{5}
This allows
1-5 Street #s
1-4 Street description words
1-3 City words
2 Char State
5 Char Zip code
I also added option , for separating street, city, state, zip

Here is the approach I have taken to finding addresses using regular expressions:
A set of patterns is useful to find many forms that we might expect from an address starting with simply a number followed by set of strings (ex. 1 Basic Road) and then getting more specific such as looking for "P.O. Box", "c/o", "attn:", etc.
Below is a simple test in python. The test will find all the addresses but not the last 4 items which are company names. This example is not comprehensive, but can be altered to suit your needs and catch examples you find in your data.
import re
strings = [
'701 FIFTH AVE',
'2157 Henderson Highway',
'Attn: Patent Docketing',
'HOLLYWOOD, FL 33022-2480',
'1940 DUKE STREET',
'111 MONUMENT CIRCLE, SUITE 3700',
'c/o Armstrong Teasdale LLP',
'1 Almaden Boulevard',
'999 Peachtree Street NE',
'P.O. BOX 2903',
'2040 MAIN STREET',
'300 North Meridian Street',
'465 Columbus Avenue',
'1441 SEAMIST DR.',
'2000 PENNSYLVANIA AVENUE, N.W.',
'465 Columbus Avenue',
'28 STATE STREET',
'P.O, Drawer 800889.',
'2200 CLARENDON BLVD.',
'840 NORTH PLANKINTON AVENUE',
'1025 Connecticut Avenue, NW',
'340 Commercial Street',
'799 Ninth Street, NW',
'11318 Lazarro Ln',
'P.O, Box 65745',
'c/o Ballard Spahr LLP',
'8210 SOUTHPARK TERRACE',
'1130 Connecticut Ave., NW, Suite 420',
'465 Columbus Avenue',
"BANNER & WITCOFF , LTD",
"CHIP LAW GROUP",
"HAMMER & ASSOCIATES, P.C.",
"MH2 TECHNOLOGY LAW GROUP, LLP",
]
patterns = [
"c\/o [\w ]{2,}",
"C\/O [\w ]{2,}",
"P.O\. [\w ]{2,}",
"P.O\, [\w ]{2,}",
"[\w\.]{2,5} BOX [\d]{2,8}",
"^[#\d]{1,7} [\w ]{2,}",
"[A-Z]{2,2} [\d]{5,5}",
"Attn: [\w]{2,}",
"ATTN: [\w]{2,}",
"Attention: [\w]{2,}",
"ATTENTION: [\w]{2,}"
]
contact_list = []
total_count = len(strings)
found_count = 0
for string in strings:
pat_no = 1
for pattern in patterns:
match = re.search(pattern, string.strip())
if match:
print("Item found: " + match.group(0) + " | Pattern no: " + str(pat_no))
found_count += 1
pat_no += 1
print("-- Total: " + str(total_count) + " Found: " + str(found_count))

UiPath Academy training video lists this RegEx for US addresses (and it works fine for me):
\b\d{1,8}(-)?[a-z]?\W[a-z|\W|\.]{1,}\W(road|drive|avenue|boulevard|circle|street|lane|waylrd\.|st\.|dr\.|ave\.|blvd\.|cir\.|In\.|rd|dr|ave|blvd|cir|ln)

I had a different use case - find any addresses in logs and scold application developers (favourite part of a devops job). I had the advantage of having the word "address" in the pattern but should work without that if you have specific field to scan
\baddress.[0-9\\\/# ,a-zA-Z]+[ ,]+[0-9\\\/#, a-zA-Z]{1,}
Look for the word "address" - skip this if not applicable
Look for first part numbers, letters, #, space - Unit Number / street number/suite number/door number
Separated by a space or comma
Look for one or more of rest of address numbers, letters, #, space
Tested against :
1 Sleepy Boulevard PO, Box 65745
Suite #100 /98,North St,Snoozepura
Ave., New Jersey,
Suite 420 1130 Connect Ave., NW,
Suite 420 19 / 21 Old Avenue,
Suite 12, Springfield, VIC 3001
Suite#100/98 North St Snoozepura
This worked for me when there were street addresses with unit/suite numbers, zip codes, only street. It also didn't match IP addresses or mac addresses. Worked with extra spaces.
This assumes users are normal people separate elements of a street address with a comma, hash sign, or space and not psychopaths who use characters like "|" or ":"!

For French address and some international address too, I use it.
[\\D+ || \\d]+\\d+[ ||,||[A-Za-z0-9.-]]+(?:[Rue|Avenue|Lane|... etcd|Ln|St]+[ ]?)+(?:[A-Za-z0-9.-](.*)]?)

I was inspired from the responses given here and came with those 2 solutions
support optional uppercase
support french also
regex structure
numbers (required)
letters, chars and spaces
at least one common address keyword (required)
as many chars you want before the line break
definitions:
accuracy
capacity of detecting addresses and not something that looks like an address which is not.
range
capacity to detect uncommon addresses.
Regex 1:
high accuracy
low range
/[0-9]+[ |[a-zà-ú.,-]* ((highway)|(autoroute)|(north)|(nord)|(south)|(sud)|(east)|(est)|(west)|(ouest)|(avenue)|(lane)|(voie)|(ruelle)|(road)|(rue)|(route)|(drive)|(boulevard)|(circle)|(cercle)|(street)|(cer\.)|(cir\.)|(blvd\.)|(hway\.)|(st\.)|(aut\.)|(ave\.)|(ln\.)|(rd\.)|(hw\.)|(dr\.)|(a\.))([ .,-]*[a-zà-ú0-9]*)*/i
regex 2:
low accuracy
high range
/[0-9]*[ |[a-zà-ú.,-]* ((highway)|(autoroute)|(north)|(nord)|(south)|(sud)|(east)|(est)|(west)|(ouest)|(avenue)|(lane)|(voie)|(ruelle)|(road)|(rue)|(route)|(drive)|(boulevard)|(circle)|(cercle)|(street)|(cer\.?)|(cir\.?)|(blvd\.?)|(hway\.?)|(st\.?)|(aut\.?)|(ave\.?)|(ln\.?)|(rd\.?)|(hw\.?)|(dr\.?)|(a\.))([ .,-]*[a-zà-ú0-9]*)*/i

This one works well for me
^(\d+) ?([A-Za-z](?= ))? (.*?) ([^ ]+?) ?((?<= )APT)? ?((?<= )\d*)?$
Source : https://community.alteryx.com/t5/Alteryx-Designer-Discussions/RegEx-Addresses-different-formats-and-headaches/td-p/360147

Here is my RegEx for address, city & postal validation rules
validation rules:
address -
1 - 40 characters length.
Letters, numbers, space and . , : ' #
city -
1 - 19 characters length
Only Alpha characters are allowed
Spaces are allowed
postalCode -
The USA zip must meet the following criteria and is required:
Minimum of 5 digits (9 digits if zip + 4 is provided)
Numeric only
A Canadian postal code is a six-character string.
in the format A1A 1A1, where A is a letter and 1 is a digit.
a space separates the third and fourth characters.
do not include the letters D, F, I, O, Q or U.
the first position does not make use of the letters W or Z.
address: ^[a-zA-Z0-9 .,#;:'-]{1,40}$
city: ^[a-zA-Z ]{1,19}$
usaPostal: ^([0-9]{5})(?:[-]?([0-9]{4}))?$
canadaPostal : ^(?!.*[DFIOQU])[A-VXY][0-9][A-Z] ?[0-9][A-Z][0-9]$

\b(\d{1,8}[a-z]?[0-9\/#- ,a-zA-Z]+[ ,]+[.0-9\/#, a-zA-Z]{1,})\n

A more dynamic approach to #micah would be the following:
(?'Address'(?'Street'[0-9][a-zA-Z\s]),?\s*(?'City'[A-Za-z\s]),?\s(?'Country'[A-Za-z])\s(?'Zipcode'[0-9]-?[0-9]))
It won't care about individual lengths of segments of code.
https://regex101.com/r/nuy7hB/1

Extract a portion of text using RegEx

I would like to extract portion of a text using a regular expression. So for example, I have an address and want to return just the number and streets and exclude the rest:
2222 Main at King Edward Vancouver BC CA
But the addresses varies in format most of the time. I tried using Lookbehind Regex and came out with this expression:
.*?(?=\w* \w* \w{2}$)
The above expressions handles the above example nicely but then it gets way too messy as soon as commas come into the text, postal codes which can be a 6 character string or two 3 character strings with a space in the middle, etc...
Is there any more elegant way of extracting a portion of text other than a lookbehind regex?
Any suggestion or a point in another direction is greatly appreciated.
Thanks!

Regular expressions are for data that is REGULAR, that follows a pattern. So if your data is completely random, no, there's no elegant way to do this with regex.
On the other hand, if you know what values you want, you can probably write a few simple regexes, and then just test them all on each string.
Ex.
regex1= address # grabber, regex2 = street type grabber, regex3 = name grabber.
Attempt a match on string1 with regex1, regex2, and finally regex3. Move on to the next string.

well i thot i'd throw my hat into the ring:
.*(?=,? ([a-zA-Z]+,?\s){3}([\d-]*\s)?)
and you might want ^ or \d+ at the front for good measure
and i didn't bother specifying lengths for the postal codes... just any amount of characters hyphens in this one.
it works for these inputs so far and variations on comas within the City/state/country area:
2222 Main at King Edward Vancouver, BC, CA, 333-333
555 road and street place CA US 95000
2222 Main at King Edward Vancouver BC CA 333
555 road and street place CA US
it is counting at there being three words at the end for the city, state and country but other than that it's like ryansstack said, if it's random it won't work. if the city is two words like New York it won't work. yeah... regex isn't the tool for this one.
btw: tested on regexhero.net

i can think of 2 ways you can do this
1) if you know that "the rest" of your data after the address is exactly 2 fields, ie BC and CA, you can do split on your string using space as delimiter, remove the last 2 items.
2) do a split on delimiter /[A-Z][A-Z]/ and store the result in array. then print out the array ( this is provided that the address doesn't contain 2 or more capital letters)