*
 * Each entry is 4 bytes, and represents a _range_ of code points that all share a common 14-bit
 * prefix. Entries are sorted by their complete code points.
 *
 * The 4 bytes are named b0, b1, b2 and b3. We also define these supplemental values:
 *
 *  * **b2a**: b2 + 0x80
 *  * **b3a**: b3 + 0x80
 *  * **b2b3**: (b2 << 7) + b3
 *
 * b0
 * --
 *

{{- define "mesh" }}
    # The trust domain corresponds to the trust root of a system.
    # Refer to https://github.com/spiffe/spiffe/blob/master/standards/SPIFFE-ID.md#21-trust-domain
    trustDomain: "cluster.local"

    # The namespace to treat as the administrative root namespace for Istio configuration.
    # When processing a leaf namespace Istio will search for declarations in that namespace first

If you can use the **latest versions of Python**, use the examples for the latest version, those will have the **best and simplest syntax**, for example, "**Python 3.10+**".

#### List

For example, let's define a variable to be a `list` of `str`.

=== "Python 3.9+"

    Declare the variable, with the same colon (`:`) syntax.

    As the type, put `list`.

{{- /* Core defines the common configuration used by all webhook segments */}}
{{/* Copy just what we need to avoid expensive deepCopy */}}
{{- $whv := dict
 "revision" .Values.revision
  "injectionPath" .Values.istiodRemote.injectionPath
  "injectionURL" .Values.istiodRemote.injectionURL
  "reinvocationPolicy" .Values.sidecarInjectorWebhook.reinvocationPolicy
  "caBundle" .Values.istiodRemote.injectionCABundle
  "namespace" .Release.Namespace }}
{{- define "core" }}

* API usage monitoring systems
* response data injection systems
* etc.

## Simple and Powerful

Although the hierarchical dependency injection system is very simple to define and use, it's still very powerful.

You can define dependencies that in turn can define dependencies themselves.

# Request Files

You can define files to be uploaded by the client using `File`.

!!! info
    To receive uploaded files, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

    E.g. `pip install python-multipart`.

    This is because uploaded files are sent as "form data".

## Import `File`

Import `File` and `UploadFile` from `fastapi`:

=== "Python 3.9+"

    * Because pydantic data structures are just instances of classes you define; auto-completion, linting, mypy and your intuition should all work properly with your validated data.
* Validate **complex structures**:
    * Use of hierarchical Pydantic models, Python `typing`’s `List` and `Dict`, etc.
    * And validators allow complex data schemas to be clearly and easily defined, checked and documented as JSON Schema.

{{- /* Core defines the common configuration used by all webhook segments */}}
{{/* Copy just what we need to avoid expensive deepCopy */}}
{{- $whv := dict
 "revision" .Values.revision
  "injectionPath" .Values.istiodRemote.injectionPath
  "injectionURL" .Values.istiodRemote.injectionURL
  "reinvocationPolicy" .Values.sidecarInjectorWebhook.reinvocationPolicy
  "caBundle" .Values.istiodRemote.injectionCABundle
  "namespace" .Release.Namespace }}
{{- define "core" }}

   * first decrementing to zero, and then removing. putIfAbsent or replace could observe the
   * intermediate zero-state. Ways we could deal with this are:
   *
   * - Don't define any of the ConcurrentMap operations. This is the current state of affairs.
   *
   * - Define putIfAbsent and replace as treating zero and absent identically (as currently
   *   implemented below). This is a bit surprising with putIfAbsent, which really becomes

**FastAPI** will know that it can use this dependency to define a "security scheme" in the OpenAPI schema (and the automatic API docs).

!!! info "Technical Details"