Para entender las variables de entorno, puedes leer [Variables de Entorno](../environment-variables.md).

///

## Tipos y validación { #types-and-validation }

Estas variables de entorno solo pueden manejar strings de texto, ya que son externas a Python y tienen que ser compatibles con otros programas y el resto del sistema (e incluso con diferentes sistemas operativos, como Linux, Windows, macOS).

limitations under the License.
==============================================================================*/

#include <memory>
#include <utility>
#include <vector>

#include "absl/strings/str_cat.h"
#include "tensorflow/c/c_api.h"
#include "tensorflow/c/eager/abstract_context.h"
#include "tensorflow/c/eager/c_api_internal.h"
#include "tensorflow/c/eager/c_api_unified_experimental.h"

    // These contain bytes not in the decodabet.
    assertFailsToDecode(base16(), "\n\n", "Unrecognized character: 0xa");
    assertFailsToDecode(base16(), "EFGH", "Unrecognized character: G");
    // Valid base16 strings always have an even length.
    assertFailsToDecode(base16(), "A", "Invalid input length 1");
    assertFailsToDecode(base16(), "ABC");
    // These have a combination of invalid length and unrecognized characters.

 * status values, field names, date/time formats, authentication types, and various reserved words and patterns.
 *
 * <p>Key constant categories include:</p>
 * <ul>
 * <li>System configuration property keys</li>
 * <li>Default values for crawling and indexing operations</li>
 * <li>User agent strings and patterns for web crawling</li>

dem Code (Python) entnimmt und in etwas umwandelt, was durch das Netzwerk gesendet werden kann. Beispielsweise das Konvertieren eines Objekts, welches Daten aus einer Datenbank enthält, in ein JSON-Objekt. Konvertieren von `datetime`-Objekten in Strings, usw.

Eine weitere wichtige Funktion, benötigt von APIs, ist die Datenvalidierung, welche sicherstellt, dass die Daten unter gegebenen Umständen gültig sind. Zum Beispiel, dass ein Feld ein `int` ist und kein zufälliger String. Das ist...

  public void add(double x, double y) {
    // We extend the recursive expression for the one-variable case at Art of Computer Programming
    // vol. 2, Knuth, 4.2.2, (16) to the two-variable case. We have two value series x_i and y_i.
    // We define the arithmetic means X_n = 1/n \sum_{i=1}^n x_i, and Y_n = 1/n \sum_{i=1}^n y_i.
    // We also define the sum of the products of the differences from the means

                    "Invalid query: " + queryContext.getQueryString(), e);
        }
    }

    /**
     * Gets the query parser instance for parsing search query strings.
     *
     * @return the configured query parser
     */
    protected QueryParser getQueryParser() {
        return ComponentUtil.getQueryParser();
    }

    /**

/* encdec - encode and decode integers, times, and
 * internationalized strings to and from popular binary formats
 * http://www.ioplex.com/~miallen/encdec/
 * Copyright (c) 2003 Michael B. Allen <******@****.***>
 *
 * The GNU Library General Public License
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either

</div>

於是，你在全域 Python 環境中安裝了 `harry` 版本 `3`。

如果你再次嘗試運行 `philosophers-stone`，很可能會**無法正常運作**，因為它需要的是 `harry` 版本 `1`。

```mermaid
flowchart LR
    subgraph global[全域環境]
        harry-1[<strike>harry v1</strike>]
        style harry-1 fill:#ccc,stroke-dasharray: 5 5
        harry-3[harry v3]
    end
    subgraph stone-project[專案 philosophers-stone]
        stone(philosophers-stone) -.-x|⛔️| harry-1
    end

</div>

于是，你在你的全局 Python 环境中安装了 `harry` 版本 `3`。

如果你再次尝试运行 `philosophers-stone`，有可能它**无法正常工作**，因为它需要 `harry` 版本 `1`。

```mermaid
flowchart LR
    subgraph global[全局环境]
        harry-1[<strike>harry v1</strike>]
        style harry-1 fill:#ccc,stroke-dasharray: 5 5
        harry-3[harry v3]
    end
    subgraph stone-project[工程 philosophers-stone]
        stone(philosophers-stone) -.-x|⛔️| harry-1
    end