Removing special characters while retaining alpha numeric words - regex

I'm in the middle of cleaning a data set that has this:
[IN]
my_Series = pd.Series(["-","ASD", "711-AUG-M4G","Air G2G", "Karsh"])
my_Series.str.replace("[^a-zA-Z]+", " ")
[OUT]
0
1 ASD
2 AUG M G
3 Air G G
4 Karsh
[IDEAL OUT]
0
1 ASD
2 AUG M4G
3 Air G2G
4 Karsh
My goal is to remove special characters and numbers but it there's a word that contains alphanumeric, it should stay. Can anyone help?

Try with apply to achieve your ideal output.
>>> my_Series = pd.Series(["-","ASD", "711-AUG-M4G","Air G2G", "Karsh"])
Output:
>>> my_Series.apply(lambda x: " ".join(['' if word.isdigit() else word for word in x.replace('-', ' ').split()]))
0
1 ASD
2 AUG M4G
3 Air G2G
4 Karsh
dtype: object
Explanation:
I have replaced - with space and split string on spaces. Then check whether the word is digit or not.
If it is digit replace with empty string else with actual word.
At last we are joining the list.
Edit 1:
regex solution :-
>>> my_Series.str.replace("((\d+)(?=.*\d))|([^a-zA-Z0-9 ])", " ")
0
1 ASD
2 AUG M4G
3 Air G2G
4 Karsh
dtype: object
Explanation:
Using lookaround.
((\d+)(?=.*\d))|([^a-zA-Z0-9 ])
(A number is last if it is followed by any other number) OR (allows alpha numeric)

Related

Detecting Special Characters with Regular Expression in python?

df
Name
0 ##
1 R##
2 ghj##
3 Ray
4 *#+
5 Jack
6 Sara123#
7 ( 1234. )
8 Benjamin k 123
9 _
10 _!##_
11 _#_&#+-
12 56##!
Output:
Bad_Name
0 ##
1 *#+
2 _
3 _!##_
4 _#_&#+-
I need to detect the special character through regular expression. If a string contains any alphabet or Number then that string is valid else it will consider as bad string.
I was using '^\W*$' RE, everything was working fine except when the string contains '_'( underscore) it is not treating as Bad String.
Use pandas.Series.str.contains:
df[~df['Name'].str.contains('[a-z0-9]', False)]
Output:
Name
0 ##
4 *#+
9 _
10 _!##_
11 _#_&#+-

dart regex remove space phone

I tried all this regex solution but no match REGEX Remove Space
I work with dart and flutter and I tried to capture only digit of this type of string :
case 1
aaaaaaaaa 06 12 34 56 78 aaaaaa
case 2
aaaaaaaa 0612345678 aaaaaa
case 3
aaaaaa +336 12 34 56 78 aaaaa
I search to have only 0612345678 with no space and no +33. Just 10 digit in se case of +33 I need to replace +33 by 0
currently I have this code \D*(\d+)\D*? who run with the case 2
You may match and capture an optional +33 and then a digit followed with spaces or digits, and then check if Group 1 matched and then build the result accordingly.
Here is an example solution (tested):
var strs = ['aaaaaaaaa 06 12 34 56 78 aaaaaa', 'aaaaaaaa 0612345678 aaaaaa', 'aaaaaa +336 12 34 56 78 aaaaa', 'more +33 6 12 34 56 78'];
for (int i = 0; i < strs.length; i++) {
var rx = new RegExp(r"(?:^|\D)(\+33)?\s*(\d[\d ]*)(?!\d)");
var match = rx.firstMatch(strs[i]);
var result = "";
if (match != null) {
if (match.group(1) != null) {
result = "0" + match.group(2).replaceAll(" ", "");
} else {
result = match.group(2).replaceAll(" ", "");
}
print(result);
}
}
Returns 3 0612345678 strings in the output.
The pattern is
(?:^|\D)(\+33)?\s*(\d[\d ]*)(?!\d)
See its demo here.
(?:^|\D) - start of string or any char other than a digit
(\+33)? - Group 1 that captures +33 1 or 0 times
\s* - any 0+ whitespaces
(\d[\d ]*) - Group 2: a digit followed with spaces or/and digits
(?!\d) - no digit immediately to the right is allowed.
Spaces are removed from Group 2 with a match.group(2).replaceAll(" ", "") since one can't match discontinuous strings within one match operation.

regex - capture space delimited word

I have a string:
2001 970451 4 l 97 0451 iver b y c 3 0 1 8 4 1 4 hundred 2001 970451 nama 4 l 97 0451 iver hundred blah
I need an appropriate regular expression to capture series of characters and spaces such as b y c 3 0 1 8 4 1 4?
I have tried:
(\b[a-z0-9]{1}\s{1})+ - I get l
EDIT:
To further explain what I need, I need to be able to capture similar series of text where a single alphanum character is continuously/repeatedly followed by single space character to a point where this is no longer true.
Is regexp a hard requirement?
It would be far simpler for you, in the long term, to just use something like strings.Fields and filter the resulting array by length (you can apply any other requirements too).
Example:
(Give it a try on the playground! https://play.golang.org/p/Ue2wO5d-Te)
package main
import (
"fmt"
"strings"
)
func CaptureGroups(input string) (output [][]string) {
fields := strings.Fields(input)
var group []string
for _, field := range fields {
if len(field) == 1 {
group = append(group, field)
} else {
if len(group) > 0 {
output = append(output, group)
group = make([]string, 0)
}
}
}
return
}
func main() {
input := "2001 970451 4 l 97 0451 iver b y c 3 0 1 8 4 1 4 hundred 2001 970451 nama 4 l 97 0451 iver hundred blah"
output := CaptureGroups(input)
fmt.Printf("Groups: %q", output)
}
i think this will work: (( [^ ])+ )
your string will be in capture group 1
\040 matches exactly the space character.
so to match something like `b y c 3 0 1 8 4 1 4 you need
[a-z]\040[a-z]\040[a-z]\040[0-9]\040[0-9]\040[0-9]\040[0-9]

Scala Regular Expression Oddity

I have this regular expression:
^(10)(1|0)(.)(.)(.)(.{18})((AB[^|]*)\||(AQ[^|]*)\||(AJ[^|]*)\||(AF[^|]*)\||(CS[^|]*)\||(CR[^|]*)\||(CT[^|]*)\||(CK[^|]*)\||(CV[^|]*)\||(CY[^|]*)\||(DA[^|]*)\||(AO[^|]*)\|)+AY([0-9]*)AZ(.*)$
To give it a bit of organization, there's really 3 parts:
// Part 1
^(10)(1|0)(.)(.)(.)(.{18})
// Part 2
// Optional Elements that begin with two characters and is terminated by a |
// May appear at most once
((AB[^|]*)\||(AQ[^|]*)\||(AJ[^|]*)\||(AF[^|]*)\||(CS[^|]*)\||(CR[^|]*)\||(CT[^|]*)\||(CK[^|]*)\||(CV[^|]*)\||(CY[^|]*)\||(DA[^|]*)\||(AO[^|]*)\|)+
// Part 3
AY([0-9]*)AZ(.*)$
Part 2 is the part that I'm having trouble with but I believe the current regular expression says any of these given elements will appear one or more times. I could have done something like: (AB.*?|) but I don't need the pipe in my group and wasn't quite sure how to express it.
This is my sample input - it's SIP2 if you've seen it before (please disregard checksum, I know it's not valid):
101YNY201406120000091911AOa|ABb|AQc|AJd|CKe|AFf|CSg|CRh|CTi|CVj|CYk|DAl|AY1AZAA71
This is my snippet of Scala code:
val regex = """^(10)(1|0)(.)(.)(.)(.{18})((AB[^|]*)\||(AQ[^|]*)\||(AJ[^|]*)\||(AF[^|]*)\||(CS[^|]*)\||(CR[^|]*)\||(CT[^|]*)\||(CK[^|]*)\||(CV[^|]*)\||(CY[^|]*)\||(DA[^|]*)\||(AO[^|]*)\|)+AY([0-9]*)AZ(.*)$""".r
val msg = "101YNY201406120000091911AOa|ABb|AQc|AJd|CKe|AFf|CSg|CRh|CTi|CVj|CYk|DAl|AY1AZAA71"
val m = regex.findFirstMatchIn(msg)) match {
case None => println("No match")
case Some(x) =>
for (i <- 0 to x.groupCount) {
println(i + " " + x.group(i))
}
}
This is my output:
0 101YNY201406120000091911AOa|ABb|AQc|AJd|CKe|AFf|CSg|CRh|CTi|CVj|CYk|DAl|AY1AZAA71
1 10
2 1
3 Y
4 N
5 Y
6 201406120000091911
7 DAl|
8 ABb
9 AQc
10 AJd
11 AFf
12 CSg
13 CRh
14 CTi
15 CKe
16 CVj
17 CYk
18 DAl
19 AOa
20 1
21 AA71
Note the entry that starts with 7. Can anyone explain why that's there?
I'm using Scala 2.10.4 but I believe regular expressions in Scala simply uses Java's regular expression. I'm certainly open to other suggestions for parsing strings.
EDIT: Based on wingedsubmariner's response, I was able to fix my regular expression:
^(10)(1|0)(.)(.)(.)(.{18})(?:AB([^|]*)\||AQ([^|]*)\||AJ([^|]*)\||AF([^|]*)\||CS([^|]*)\||CR([^|]*)\||CT([^|]*)\||CK([^|]*)\||CV([^|]*)\||CY([^|]*)\||DA([^|]*)\||AO([^|]*)\|)+AY([0-9]*)AZ(.*)$
Basically adding ?: to indicate I was not interested in the group!
You get a matched group for each set of parentheses, the order being the order of the opening parenthesis in the regex. Matched group 7 corresponds to the opening parenthesis that begins your "Group 2":
((AB[^|]*)\||(AQ[^|]*)\||(AJ[^|]*)\||(AF[^|]*)\||(CS[^|]*)\||(CR[^|]*)\||(CT[^|]*)\||(CK[^|]*)\||(CV[^|]*)\||(CY[^|]*)\||(DA[^|]*)\||(AO[^|]*)\|)+
^
|
This parenthesis
Each matched group takes on the value of the last part of the text that matched, which in this case is DAl| because it was the last piece of text to match the "Group 2" expression.
Here is a simpler example that demonstrates the behavior:
val regex = """((A)\||(B)\|)+""".r
val msg = "A|B|A|B|"
regex.findFirstMatchIn(msg) match {
case None => println("No match")
case Some(x) =>
for (i <- 0 to x.groupCount) {
println(i + " " + x.group(i))
}
}
Which produces:
0 A|B|A|B|
1 B|
2 A
3 B

Regular Expression: Find repeated patterns

Having this string s=";123;;123;;456;;124;;123;;567;" in R, which shows some Ids separated by ";", I want to find the repeated IDs, so in this case ";123;" is repeated. I used the following command in R:
gregexpr("(;[1-9]+;).*\1", s)
but it doesn't find the repeated patterns. Any idea what is wrong?
One example of a long string:
1760381;;1774536;;1774614;;1774617;;1774705;;1774723;;1775013;;1902321;;1928678;;2105486;;2105514;;2105544;;2105575;;2105585;;2279115;;2379236;;290927;;542280;;555749;;641540;;683822;;694934;;713228;;713248;;713249;;726949;;727204;;731434;;754522;;7693856;;100095;;1003838;;1045582;;1079057;;1108697;;1231229;;124087;;1249672;;1328126;;1412065;;1419930;;1441743;;1470580;;1476585;;1502106;;1556149;;1637775;;1643922;;1655644;;1755547;;1759001;;1760295;;1760296;;1760320;;1760326;;1760338;;1760348;;1760349;;1760350;;1760353;;1760375;;1760376;;1760377;;1760378;;1760388;;1760401;;1760402;;1760403;;1760410;;1760421;;1760425;;1760426;;1760642;;1760654;;1770463;;1774365;;1774366;;1774394;;1774449;;1774453;;1774454;;1774455;;1774456;;1774457;;1774458;;1774461;;1774462;;1774463;;1774464;;1774466;;1774469;;1774504;;1774505;;1774506;;1774519;;1774520;;1774525;;1774527;;1774529;;1774532;;1774533;;1774539;;1774542;;1774593;;1774595;;1774604;;1774610;;1774616;;1774617;;1774641;;1774660;;1774671;;1774674;;1774684;;1774687;;1774694;;1774704;;1774706;;1774713;;1774717;;1774722;;1774723;;1774726;;1774733;;1774745;;1774750;;1774753;;1774754;;1774766;;1774784;;1774786;;1774795;;1774799;;1774800;;1774803;;1774809;;1774813;;1774835;;1774849;;1774852;;1774853;;1774854;;1774857;;1774858;;1774861;;1774862;;1774867;;1774868;;1774869;;1774870;;1774877;;1774878;;1774880;;1774884;;1774885;;1774886;;1774902;;1774905;;1774934;;1774935;;1774937;;1774939;;1774946;;1774949;;1774950;;1774958;;1774959;;1774960;;1774961;;1774962;;1774964;;1774965;;1774966;;1774967;;1774969;;1774971;;1774972;;1774973;;1774975;;1774977;;1774978;;1774999;;1775000;;1775003;;1775005;;1775006;;1775009;;1775013;;1775014;;1775017;;1775024;;1775026;;1775033;;1775038;;1775040;;1775041;;1775044;;1775087;;1785544;;1811645;;1837210;;1864356;;1928674;;1928678;;1932882;;1954203;;2066856;;2076876;;2105349;;2105351;;2105458;;2105464;;2105476;;2105480;;2105482;;2105484;;2105489;;2105496;;2105500;;2105510;;2105514;;2105518;;2105532;;2105545;;2105550;;2172257;;2172762;;218438;;2228198;;2229827;;2247909;;2262250;;2263135;;2287260;;2335872;;2335873;;2335874;;2335877;;2338682;;2352560;;2420902;;263946;;265370;;303060;;330571;;338764;;387492;;387750;;388362;;431807;;436056;;436442;;444058;;458026;;491696;;504783;;513098;;529228;;539799;;549649;;559957;;562574;;563116;;576418;;582851;;592273;;599952;;614463;;626416;;645122;;652363;;665854;;668048;;682877;;683822;;688317;;709795;;710684;;723114;;724447;;724526;;725177;;731389;;731434;;876958;;879962;;947924;;987322;;987446;;61326;;1025952;;1095970;;1338018;;1349990;;1373122;;1419930;;1760310;;1760320;;1774705;;1774706;;1774708;;1774712;;1774952;;1774954;;1774963;;1774972;;1774977;;1775077;;1901075;;2022080;;2117779;;2143723;;441554;;450517;;549649;;1010402;;113311;;1148258;;1374348;;1419930;;1606449;;1606515;;1606608;;1606610;;1760320;;1760338;;1760618;;1760642;;1774504;;1774520;;1774595;;1774705;;1774909;;1774977;;1775011;;1775043;;179542;;1928678;;2105598;;2105721;;2188303;;2335873;;340762;;387759;;436442;;504783;;588336;;646185;;682877;;715644;;725080;;741661;;760924
m<-gregexpr("[0-9]+",s)
n<-regmatches(s,m)
[[1]]
[1] "123" "123" "456" "124" "123" "567"
data.frame(table(unlist(n)))
Var1 Freq
1 123 3
2 124 1
3 456 1
4 567 1
The code works for your long form string too: Here is the head and tail of the output:
head(data.frame(table(unlist(n))),10)
Var1 Freq
1 100095 1
2 1003838 1
3 1010402 1
4 1025952 1
5 1045582 1
6 1079057 1
7 1095970 1
8 1108697 1
9 113311 1
10 1148258 1
tail(data.frame(table(unlist(n))),10)
Var1 Freq
316 731434 2
317 741661 1
318 754522 1
319 760924 1
320 7693856 1
321 876958 1
322 879962 1
323 947924 1
324 987322 1
325 987446 1
1) In the examples the ids are all the same length so we assume that is a general feature. Try this pattern where (?=...) is a zero width lookahead expression (see ?regex)
pat <- ";([1-9]+);(?=.*\\1)"
gregexpr(pat, s, perl = TRUE)
or this:
library(gsubfn)
strapply(s, pat, perl = TRUE)[[1]]
## [1] "123" "123"
This lists each id one fewer times than its occurrence (zero times for ids not duplicated) in s so to list each duplicated id uniquely try unique(st) where st is the result of this last line of code above.
Note: In the second example in the question, i.e. the long string, there is no ; at the end of the string so the last id can never be matched by the expression unless we first paste a ; onto the end.
2) Instead of matching the contents we could match the delimiters instead:
strsplit(s, ";")[[1]])[-1]
If st is the result of this line of code then st is just a vector of all the ids so unique(st[duplicated[st]) uniquely lists each duplicated id and involves no regular expressions.