/// check

So, with the same Python type declaration, **FastAPI** gives you data validation.

Notice that the error also clearly states exactly the point where the validation didn't pass.

This is incredibly helpful while developing and debugging code that interacts with your API.

///

## Documentation { #documentation }

     * A B node only broadcasts name queries. This is the default if a
     * nameserver such as WINS or Samba is not specified.
     */

    public static final int B_NODE = 0;

    /**
     * A Point-to-Point node, or P node, unicasts queries to a nameserver
     * only. Natrually the <code>jcifs.smb1.netbios.nameserver</code> property must
     * be set.
     */

    public static final int P_NODE = 1;

    /**

          required: false
          schema:
            type: integer
            minimum: 0
            exclusiveMinimum: false
            default: 0
            example: 0
        - name: geo.location.point
          in: query
          description: Latitude and Longitude for Geo search
          required: false
          schema:
            type: string
            example: 35.0,139.0

    if (address.url.host ==
      this
        .route()
        .address.url.host
    ) {
      return true // This connection is a perfect match.
    }

    // At this point we don't have a hostname match. But we still be able to carry the request if
    // our connection coalescing requirements are met. See also:
    // https://hpbn.co/optimizing-application-delivery/#eliminate-domain-sharding

                            return response.addrEntry[0];
                        }
                        if (element == RESOLVER_WINS) {
                            /* If WINS reports negative, no point in retry
                             */
                            break;
                        }
                    }
                    break;
                }

{* ../../docs_src/first_steps/tutorial001.py hl[3] *}

Here the `app` variable will be an "instance" of the class `FastAPI`.

This will be the main point of interaction to create all your API.

### Step 3: create a *path operation* { #step-3-create-a-path-operation }

#### Path { #path }

"Path" here refers to the last part of the URL starting from the first `/`.

    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**
   * Parses the specified string as a single-precision floating point value. The ASCII character
   * {@code '-'} (<code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Float#parseFloat(String)}, this method returns {@code null} instead of

      // TODO(user): verify future behavior - unify logic with getFutureValue in AbstractFuture. This
      // code should be unreachable with correctly implemented Futures.
      // Cancel this future and return.
      // At this point, inputFuture is cancelled and outputFuture doesn't exist, so the value of
      // mayInterruptIfRunning is irrelevant.
      cancel(false);
      return;
    } catch (ExecutionException e) {

### The Problem { #the-problem }

So, what's the problem with installing packages in the global Python environment?

At some point, you will probably end up writing many different programs that depend on **different packages**. And some of these projects you work on will depend on **different versions** of the same package. 😱

          shift += 24;
          len += 3;
        } else {
          int codePoint = Character.codePointAt(input, i);
          if (codePoint == c) {
            // not a valid code point; let the JDK handle invalid Unicode
            return hashBytes(input.toString().getBytes(charset));
          }
          i++;
          buffer |= codePointToFourUtf8Bytes(codePoint) << shift;