# Query Parameters and String Validations

**FastAPI** allows you to declare additional information and validation for your parameters.

Let's take this application as example:

//// tab | Python 3.10+

```Python hl_lines="7"
{!> ../../docs_src/query_params_str_validations/tutorial001_py310.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="9"
{!> ../../docs_src/query_params_str_validations/tutorial001.py!}
```

A GODEBUG setting is a `key=value` pair
that controls the execution of certain parts of a Go program.
The environment variable `GODEBUG`
can hold a comma-separated list of these settings.
For example, if a Go program is running in an environment that contains

	GODEBUG=http2client=0,http2server=0

then that Go program will disable the use of HTTP/2 by default in both
the HTTP client and the HTTP server.

policy grants access to buckets with name starting with example. ## In addition, grants objects read permissions on buckets starting with example. # - name: readonlyexamplepolic # statements: # - resources: # - 'arn:aws:s3:::example*/*' # actions: # - "s3:GetObject" # - resources: # - 'arn:aws:s3:::example*' # actions: # - "s3:GetBucketLocation" # - "s3:ListBucket" # - "s3:ListBucketMultipartU" ## conditionsexample policy creates all access to example bucket with aws:username="johndoe" and source ip range...

policy grants access to buckets with name starting with example. ## In addition, grants objects read permissions on buckets starting with example. # - name: readonlyexamplepolic # statements: # - resources: # - 'arn:aws:s3:::example*/*' # actions: # - "s3:GetObject" # - resources: # - 'arn:aws:s3:::example*' # actions: # - "s3:GetBucketLocation" # - "s3:ListBucket" # - "s3:ListBucketMultipartU" ## conditionsexample policy creates all access to example bucket with aws:username="johndoe" and source ip range...

 * JavaScript parser `urltestparser.js` with which this class attempts to be compatible.
 *
 * Each line of the `urltestdata.txt` file specifies a test. Lines look like this:
 *
 * ```
 * http://example\t.\norg http://example.org/foo/bar s:http h:example.org p:/
 * ```
 */
class WebPlatformUrlTestData {
  var input: String? = null
  var base: String? = null
  var scheme = ""
  var username = ""

policy grants access to buckets with name starting with example. ## In addition, grants objects read permissions on buckets starting with example. # - name: readonlyexamplepolic # statements: # - resources: # - 'arn:aws:s3:::example*/*' # actions: # - "s3:GetObject" # - resources: # - 'arn:aws:s3:::example*' # actions: # - "s3:GetBucketLocation" # - "s3:ListBucket" # - "s3:ListBucketMultipartU" ## conditionsexample policy creates all access to example bucket with aws:username="johndoe" and source ip range...

        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$2b$12$gSvqqUPvlXP2tfVFaWK1Be7DlH.PKZbv5H8KnzzVgXXbVxpva.pFm",

from ...utils import needs_pydanticv2


@needs_pydanticv2
def test_settings(monkeypatch: MonkeyPatch):
    from docs_src.settings.app02 import main

    monkeypatch.setenv("ADMIN_EMAIL", "admin@example.com")
    settings = main.get_settings()
    assert settings.app_name == "Awesome API"
    assert settings.items_per_user == 50


@needs_pydanticv2
def test_override_settings():

ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIDVGk/SRz4fwTPK0+Ra7WYUGf3o08YkpI0yTMPpHwYoq dillon@example.io...

writeexamplepolicy policy grants creation or deletion of buckets with name ## starting with example. In addition, grants objects write permissions on buckets starting with ## example. # - name: writeexamplepolicy # statements: # - resources: # - 'arn:aws:s3:::example*/*' # actions: # - "s3:AbortMultipartUpload" # - "s3:GetObject" # - "s3:DeleteObject" # - "s3:PutObject" # - "s3:ListMultipartUploadP" # - resources: # - 'arn:aws:s3:::example*' # actions: # - "s3:CreateBucket" # - "s3:DeleteBucket" # - "s3:GetBucketLocation"...