/String_Matching

Primary LanguagePython

String Matching - RegEx.

Pattern Syntax

The supported metacharacters in the pattern include:

  • . (dot): Matches any single character except a newline.
  • *: Matches zero or more occurrences of the preceding character or group.
  • +: Matches one or more occurrences of the preceding character or group.
  • ?: Matches zero or one occurrence of the preceding character or group.
  • ^: Specifies the beginning of a line or string.
  • $: Specifies the end of a line or string.
  • ( and ): Groups multiple characters or expressions together.
  • |: Represents alternation, allowing either of the provided patterns to be matched.
  • [ and ]: Defines a character class, matching any single character inside the brackets.

Example

Let's say you want to find occurrences of the pattern a.*b|(c|d)[0-9] in the text azb a1b c7d89 c2b a3b.

  1. Put the pattern a.*b|(c|d)[0-9] in pattern.txt.
  2. Put the text azb a1b c7d89 c2b a3b in text.txt.
  3. Run the program using the command python string_matcher.py.

After running the program, an output.txt file will be generated with the positions where the pattern is found in the text.

Note

  • Modify pattern.txt and text.txt with your desired pattern and text.
  • Regular expressions can be powerful but might require escaping special characters. Make sure to adjust the pattern accordingly.
  • This program provides a basic example of regex pattern matching. For more complex scenarios, consider using established libraries like re in Python.
Pattern found at positions: 0, 4, 11, 15, 18

Please replace placeholders like pattern.txt and text.txt with the actual filenames you're using. This README provides a basic template, so feel free to add more details if needed.