Python Stack Trace Frame Regex for Java
/^\s*File "[^"]+", line [0-9]+, in [^\s]+$/What this pattern does
This page provides a well-structured, multi-part regular expression for matching python stack trace frame, ported and verified for Java. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Java project — whether you're validating in a Spring Boot controller, a Jakarta EE service, or a standalone utility class.
Java Implementation
// Python Stack Trace Frame
// ReDoS-safe | RegexVault — Dev & Systems > Log Parsing
import java.util.regex.Pattern;
public class PythonStackTraceFrameValidator {
private static final Pattern PATTERN =
Pattern.compile("^\\s*File \"[^\"]+\", line [0-9]+, in [^\\s]+$");
public static boolean validate(String input) {
return PATTERN.matcher(input).matches();
}
// Example
public static void main(String[] args) {
System.out.println(validate(" File "/app/main.py", line 42, in main")); // true
}
}Test Cases
Matches (Valid) | Rejects (Invalid) |
|---|---|
File "/app/main.py", line 42, in main | File main.py, line 42, in main |
File "<stdin>", line 1, in <module> | File main.py, line 42 |
File "/usr/lib/python3.11/threading.py", line 1016, in _bootstrap | Traceback (most recent call last): |
When to use this pattern
This pattern is drawn from the Dev & Systems > Log Parsing category and carries a ReDoS-safe certification. That matters for Java developers because critical in Java applications since the JVM regex engine uses backtracking and is susceptible to ReDoS without careful pattern design. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.
Common Pitfalls
<module> (top-level code) and <listcomp> (list comprehension) are valid function name fields. The pattern's [a-zA-Z_] start allows these via the <> inclusion.
Technical Notes
Groups: 1=file path (can be <stdin> or <string>), 2=line number, 3=function name (<module> for top-level code). The < > characters in group 3 handle <module>, <listcomp>, etc.
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