$ python main.py

// As we didn't set the env var, we get the default value

Hello World from Python

// But if we create an environment variable first
$ export MY_NAME="Wade Wilson"

// And then call the program again
$ python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},
 *       typically because the type forbids nullable type arguments: For example, {@code

 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},
 *       typically because the type forbids nullable type arguments: For example, {@code

 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},
 *       typically because the type forbids nullable type arguments: For example, {@code

#### Lista { #list }

Por ejemplo, vamos a definir una variable para ser una `list` de `str`.

Declara la variable, con la misma sintaxis de dos puntos (`:`).

Como tipo, pon `list`.

Como la lista es un tipo que contiene algunos tipos internos, los pones entre corchetes:

    /**
     * Adds the environment variables in the form of properties whose keys are prefixed with {@code env.}, e.g. {@code
     * env.PATH}. Unlike native environment variables, properties are always case-sensitive. For the sake of
     * determinism, the environment variable names will be normalized to upper case on platforms with case-insensitive
     * variable lookup.
     *

                    .parser(parser)
                    .variable(LineReader.LIST_MAX, 50) // max tab completion candidates
                    .variable(LineReader.HISTORY_FILE, history)
                    .variable(LineReader.OTHERS_GROUP_NAME, "Others")
                    .variable(LineReader.COMPLETION_STYLE_GROUP, "fg:blue,bold")
                    .variable("HELP_COLORS", "ti=1;34:co=38:ar=3:op=33:de=90")

 * non-ASCII input.
 *
 * @author Mike Bostock
 * @since 1.0
 */
@GwtCompatible
public enum CaseFormat {
  /**
   * Hyphenated variable naming convention, e.g., "lower-hyphen". This format is also colloquially
   * known as "kebab case".
   */
  LOWER_HYPHEN(CharMatcher.is('-'), "-") {
    @Override
    String normalizeWord(String word) {

import static com.google.common.base.Preconditions.checkArgument;

import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import org.jspecify.annotations.Nullable;

/**
 * Captures a free type variable that can be used in {@link TypeToken#where}. For example:
 *
 * {@snippet :
 * static <T> TypeToken<List<T>> listOf(Class<T> elementType) {
 *   return new TypeToken<List<T>>() {}

////

That command will create or modify some [environment variables](environment-variables.md){.internal-link target=_blank} that will be available for the next commands.

One of those variables is the `PATH` variable.

/// tip

You can learn more about the `PATH` environment variable in the [Environment Variables](environment-variables.md#path-environment-variable){.internal-link target=_blank} section.

///