Development

Python Regex Tester (re module)

Test Python re patterns online: (?P<name>…) named groups, (?P=name) backreferences, VERBOSE patterns, findall behavior, and \g<name> replace templates — plus ready-to-paste Python code.

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Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'http://127.0.0.1:3003/en/api/tools/python-regex-tester' \
  -H 'Content-Type: application/json' \
  -d '{"pattern":"(?P<first>\\w+)\\s+(?P<last>\\w+)","subject":"Ada Lovelace, Grace Hopper","flag_i":false,"flag_m":false,"flag_s":false,"flag_x":false,"flag_a":false,"flag_g":true,"replacement":"\\g<last>, \\g<first>","unicodeClasses":true}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST http://127.0.0.1:3003/en/api/tools/python-regex-tester

Parameters

Name	Type	Required	Description
pattern	text	Yes	—
subject	textarea	No	—
flag_i	checkbox	No	—
flag_m	checkbox	No	—
flag_s	checkbox	No	—
flag_x

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-python-regex-tester": {
      "name": "python-regex-tester",
      "description": "Test Python re patterns online: (?P<name>…) named groups, (?P=name) backreferences, VERBOSE patterns, findall behavior, and \\g<name> replace templates — plus ready-to-paste Python code.",
      "baseUrl": "http://127.0.0.1:3003/mcp/sse?toolId=python-regex-tester",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "python-regex-tester",
    "arguments": {
  "pattern": "(?P<first>\\w+)\\s+(?P<last>\\w+)",
  "subject": "Ada Lovelace, Grace Hopper",
  "flag_i": false,
  "flag_m": false,
  "flag_s": false,
  "flag_x": false,
  "flag_a": false,
  "flag_g": true,
  "replacement": "\\g<last>, \\g<first>",
  "unicodeClasses": true
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

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