return appendFileterPath(buf, escape(s));
    }

    /**
     * Escapes special regex characters in a string to create a literal pattern.
     * Handles anchor characters (^ and $) specially to preserve their regex meaning.
     *
     * @param s the string to escape
     * @return an escaped regex pattern, or empty string for comments
     */
    protected String escape(final String s) {

        // -------------------------------------------------------------------------------------
        // Alright, here's the justification for all the regexp wizardry below...
        //
        // Continuum and other server-like apps may need to locate the user-level and
        // global-level settings somewhere other than ${user.home} and ${maven.home},

Now you know that whenever you need them you can use them in **FastAPI**.

### Pydantic v1 `regex` instead of `pattern` { #pydantic-v1-regex-instead-of-pattern }

Before Pydantic version 2 and before FastAPI 0.100.0, the parameter was called `regex` instead of `pattern`, but it's now deprecated.

You could still see some code using it:

//// tab | Pydantic v1

Ви також можете додати параметр `min_length`:

{* ../../docs_src/query_params_str_validations/tutorial003_an_py310.py hl[10] *}

## Додавання регулярних виразів

Ви можете визначити <abbr title="Регулярний вираз (regex або regexp) — це послідовність символів, яка визначає шаблон для пошуку в рядках.">регулярний вираз</abbr> pattern, якому має відповідати параметр:

{* ../../docs_src/query_params_str_validations/tutorial004_an_py310.py hl[11] *}

	r := dryDB.Table("`user`").Find(&User{}).Statement
	if !regexp.MustCompile("SELECT \\* FROM `user`").MatchString(r.Statement.SQL.String()) {
		t.Errorf("Table with escape character, got %v", r.Statement.SQL.String())
	}

	r = dryDB.Table("user as u").Select("name").Find(&User{}).Statement
	if !regexp.MustCompile("SELECT .name. FROM user as u WHERE .u.\\..deleted_at. IS NULL").MatchString(r.Statement.SQL.String()) {

     * Adds an include filter for URLs.
     * Only URLs matching this regular expression will be crawled.
     * @param regexp The regular expression for the include filter.
     */
    public void addIncludeFilter(final String regexp) {
        if (StringUtil.isNotBlank(regexp)) {
            urlFilter.addInclude(regexp);
        }
    }

    /**
     * Adds an exclude filter for URLs.

	if !regexp.MustCompile("SELECT .*id.*name.*updated_at.*created_at.* FROM .*users").MatchString(result.Statement.SQL.String()) {
		t.Fatalf("SQL should include selected names, but got %v", result.Statement.SQL.String())
	}

	result = DB.Session(&gorm.Session{DryRun: true}).Model(&User{}).Find(&User{}, user.ID)

      .assertLogMatch(Regex("""User-Agent: okhttp/.+"""))
      .assertLogEqual("--> END GET")
      .assertLogMatch(Regex("""<-- 200 OK $url \(\d+ms\)"""))
      .assertLogEqual("Content-Type: text/html; charset=0")
      .assertLogMatch(Regex("""Content-Length: \d+"""))
      .assertLogMatch(Regex(""))
      .assertLogEqual("Body with unknown charset")
      .assertLogMatch(Regex("""<-- END HTTP \(\d+ms, 25-byte body\)"""))

            }
        }
    }

    /**
     * Adds a client with a regular expression pattern.
     * @param regex The regular expression to match URLs.
     * @param client The CrawlerClient instance.
     */
    public void addClient(final String regex, final CrawlerClient client) {
        if (StringUtil.isBlank(regex)) {
            throw new CrawlerSystemException("A regular expression is null.");
        }

      .assertLogMatch(Regex("""callStart: Request\{method=POST, url=$url\}"""))
      .assertLogMatch(Regex("""proxySelectStart: $url"""))
      .assertLogMatch(Regex("""proxySelectEnd: \[DIRECT]"""))
      .assertLogMatch(Regex("""dnsStart: ${url.host}"""))
      .assertLogMatch(Regex("""dnsEnd: \[.+]"""))
      .assertLogMatch(Regex("""connectStart: ${url.host}/.+ DIRECT"""))
      .assertLogMatch(Regex("""connectEnd: http/1.1"""))