If not provided, it's `None` by default, here we provide `"World"` as the default value to use.

///

Then you could call that Python program:

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// Here we don't set the env var yet
$ python main.py

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

          <!-- TODO(cpovirk): Move this to the parent after making the package-list files available there. -->
          <!-- We add the link ourselves so that we can choose Java 21 over the version that -source suggests. -->
          <detectJavaApiLink>false</detectJavaApiLink>
          <offlineLinks>

        smbRandomAccessFile.readFully(buffer);
        assertArrayEquals(new byte[] { 10, 20, 30, 40, 50 }, buffer);
        // Note: There appears to be a bug in the implementation where readFully
        // incorrectly updates the file pointer twice
        assertEquals(10, smbRandomAccessFile.getFilePointer());
    }

# for other files to use.
#
# Separately, if TFCI is set *and* there are also additional TFCI_ variables
# set in the shell environment, those variables will be restored after the
# TFCI env has been loaded. This is useful for e.g. on-demand "generic" jobs
# where the user may wish to change just one option.
if [[ -z "${TFCI:-}" ]]; then

  )

# Delete modules that should be hidden from dir().
# Don't fail if these modules are not available.
# For e.g. this file will be originally placed under tensorflow/_api/v1 which
# does not have "python", "core" directories. Then, it will be copied
# to tensorflow/ which does have these two directories.

try:
  del python
except NameError:
  pass
try:
  del core

            StackOverflowError.class,
            e -> e instanceof StackOverflowError);
      }
    };

    // used under GWT, etc., since the override of this method does not exist there
    ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> exceptions() {
      return ImmutableMap.of();
    }
  }

   * even to an intermediate buffer) should be considerably more efficient than potentially
   * copying the CharSequence to a String and then calling getBytes(Charset) on that String, in
   * reality there are optimizations that make the getBytes(Charset) approach considerably faster,
   * at least for commonly used charsets like UTF-8.
   */

  @Override
  @CanIgnoreReturnValue
  public final Hasher putByte(byte b) {

}
```

And of course, you can define some parameters as required, some as having a default value, and some entirely optional:

{* ../../docs_src/query_params/tutorial006_py310.py hl[8] *}

In this case, there are 3 query parameters:

* `needy`, a required `str`.
* `skip`, an `int` with a default value of `0`.
* `limit`, an optional `int`.

/// tip

      return new ThrowingCreator();
    }

    // Android isolates apps' temporary directories since Jelly Bean:
    // https://github.com/google/guava/issues/4011#issuecomment-770020802
    // So we can create files there with any permissions and still get security from the isolation.
    return new JavaIoCreator();
  }

  /**
   * Creates the permissions normally used for Windows filesystems, looking up the user afresh, even

 *
 * Code Points in Sections
 * =======================
 *
 * The full range of code points is 0..0x10fffe. We can represent any of these code points with 21
 * bits.
 *
 * We split each code point into a 14-bit prefix and a 7-bit suffix. All code points with the same
 * prefix are called a 'section'. There are 128 code points per section.
 *
 * Ranges Data (32,612 bytes)
 * ==========================
 *