{* ../../docs_src/path_params/tutorial005_py39.py hl[16] *}

### Check the docs { #check-the-docs }

Because the available values for the *path parameter* are predefined, the interactive docs can show them nicely:

<img src="/img/tutorial/path-params/image03.png">

### Working with Python *enumerations* { #working-with-python-enumerations }

The value of the *path parameter* will be an *enumeration member*.

        int length = 32;

        Hexdump.hexdump(ps, data, offset, length);
        String output = baos.toString();

        assertNotNull(output);
        // Should start at offset 0 in display but show data from offset 16
        assertTrue(output.contains("00000:"));
        // First byte should be 0x10 (16 in decimal)
        assertTrue(output.contains(" 10 11 12"));
    }

    @Test

          restore-keys: |
            master-${{ runner.os }}-
            master-

      - name: Set up Maven
        shell: bash
        run: mvn --errors --batch-mode --show-version org.apache.maven.plugins:maven-wrapper-plugin:3.3.4:wrapper "-Dmaven=4.0.0-rc-4"

      - name: Prepare Mimir for Maven 4.x
        shell: bash
        run: |
          rm .mvn/extensions.xml

  override fun toString(): String = path.joinToString(separator = " / ")

  companion object {
    /**
     * A synthetic value that indicates there's no more bytes. Values with equivalent data may also
     * show up in ASN.1 streams to also indicate the end of SEQUENCE, SET or other constructed
     * value.
     */
    private val END_OF_DATA =
      DerHeader(
        tagClass = DerHeader.TAG_CLASS_UNIVERSAL,

So, what we will do next is add the code to document how that *external API* should look like to receive the callback from *your API*.

That documentation will show up in the Swagger UI at `/docs` in your API, and it will let external developers know how to build the *external API*.

This example doesn't implement the callback itself (that could be just a line of code), only the documentation part.

///

/// warning

Have in mind that the `RequestValidationError` contains the information of the file name and line where the validation error happens so that you can show it in your logs with the relevant information if you want to.

    }

    // -----------------------------------------------------
    //                                     Parameter Logging
    //                                     -----------------
    // logging filter cannot show the parameters when multi-part so logging here
    protected void showFieldLoggingTitle() {
        if (logger.isDebugEnabled()) {
            logger.debug("[Multipart Request Parameter]");
        }
    }

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

///

padding-y:0.25rem;--bs-btn-padding-x:0.5rem;--bs-btn-font-size:0.875rem;--bs-btn-border-radius:var(--bs-border-radius-sm)}.fade{transition:opacity .15s linear}@media (prefers-reduced-motion:reduce){.fade{transition:none}}.fade:not(.show){opacity:0}.collapse:not(.show){display:none}.collapsing{height:0;overflow:hidden;transition:height .35s ease}@media (prefers-reduced-motion:reduce){.collapsing{transition:none}}.collapsing.collapse-horizontal{width:0;height:auto;transition:width .35s ease}@media...

</div>

I'm the creator of **FastAPI**. You can read more about that in [Help FastAPI - Get Help - Connect with the author](help-fastapi.md#connect-with-the-author){.internal-link target=_blank}.

...But here I want to show you the community.

---

**FastAPI** receives a lot of support from the community. And I want to highlight their contributions.

These are the people that: