Comparison of regular expressions between Python and Java

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Catalogue

Simple batch replacement

Complex template replacement

Summary

Simple batch replacement

Example: replace and in batches with & &

Python implementation

Import redef transformSimple (fromRegex,toText,inText): return re.sub (fromRegex,toText,inText, flags = re.I) if _ _ name__ = = "_ _ main__": inText = "x = 1 and y = 2" fromRegex = "and" toText = "& &" outText = transformSimple (fromRegex,toText,inText) print (outText) # # OUTPUT: X = 1 & & y = 2

Java implementation

Import java.util.*;import java.util.regex.*;public class RegexTest {private static String transformSimple (String regexPattern, String replText, String inText) {return Pattern.compile (regexPattern, Pattern.CASE_INSENSITIVE) .matcher (inText) .replaceAll (replText);} public static void main (String [] args) {String input = "x = 1 and y = 2"; String patternString = "and"; String toText = "&" String outText = ""; outText = transformSimple (patternString, toText, input); System.out.println ("RESULT:" + outText);} / / RESULT: X = 1 & & y = 2 complex template replacement

For example: replace x in (1pm 2) in batches with [1JI 2] .quote (x)

Analysis: templated

Enter packet capture (\ S+)\ s+in\ s *\ ((. +?)\)

Fill in [@ 2] .packets (@ 1)-@ 1 and @ 2 corresponding to group 1 and group 2 in the packet capture, respectively.

Python implementation

Import redef transformComplex (fromRegex, toText, inText): regObj = re.compile (fromRegex, flags = re.I) for match in regObj.finditer (inText): index = 1 outText = toText for group in match.groups (): outText = outText.replace ("@" + str (index), group) index + = 1 inText = inText.replace (match.group (0) OutText) return inTextif _ _ name__ = = "_ _ main__": fromRegex = "(\ S+)\ s+in\ s*\ ((. +?)\)" toText = "[@ 2] .in (@ 1)" inText = "x in (1pr 2) and y in (3pr 4)" outText22 = transformComplex (fromRegex, toText, inText) print (outText22) # # OUTPUT: [1Jue 2].

Java implementation

Import java.util.*;import java.util.regex.*;public class RegexTest {private static String transformComplex (String regexPattern, String replText, String inText) {Pattern pattern = Pattern.compile (regexPattern, Pattern.CASE_INSENSITIVE); Matcher matcher = pattern.matcher (inText); String outText = ""; while (matcher.find ()) {outText = replText; for (int I = 1; I)