但现在想象你要从零开始写它。

在某个时刻你开始定义函数，并且准备好了参数……

接下来你需要调用“那个把首字母变大写的方法”。

是 `upper`？是 `uppercase`？`first_uppercase`？还是 `capitalize`？

然后，你试试程序员的老朋友——编辑器的自动补全。

你输入函数的第一个参数 `first_name`，再输入一个点（`.`），然后按下 `Ctrl+Space` 触发补全。

但很遗憾，没有什么有用的提示：

<img src="/img/python-types/image01.png">

### 添加类型 { #add-types }

我们来改前一个版本的一行代码。

把函数参数从：

```Python
    first_name, last_name
```

改成：

```Python

    private static final Object[] OBJECT_ARGS = new Object[0];

    /**
     * Use a WeakHashMap here, so the keys (Class objects) can be garbage collected.
     * This approach prevents permgen space overflows due to retention of discarded
     * classloaders.
     */
    private static final Map<Class<?>, WeakReference<ClassMap>> CLASS_MAPS = new WeakHashMap<>();

    static final int EOF = -1;

	// credElement is fetched first to skip replacing the space in access key.
	credElement := strings.TrimPrefix(strings.Split(strings.TrimSpace(v4Auth), ",")[0], signV4Algorithm)
	// Replace all spaced strings, some clients can send spaced
	// parameters and some won't. So we pro-actively remove any spaces
	// to make parsing easier.
	v4Auth = strings.ReplaceAll(v4Auth, " ", "")
	if v4Auth == "" {

        monitor.leave();
      }
    } else {
      return false;
    }
  }

  /**
   * Inserts the specified element at the tail of this queue, waiting up to the specified wait time
   * for space to become available if the queue is full.
   *
   * @throws InterruptedException {@inheritDoc}
   * @throws NullPointerException {@inheritDoc}
   */
  @CanIgnoreReturnValue
  @Override

  #   Needed for removing poorly interpreted newline sequences when running in more
  #   exotic environments such as mingw bash on Windows.
  printf "%s" "${1}" | tr -d '[:space:]'
}

# parse distributionUrl and optional distributionSha256Sum, requires .mvn/wrapper/maven-wrapper.properties
while IFS="=" read -r key value; do
  case "${key-}" in

	return -1
}

// getServerPoolsAvailableSpace will return the available space of each pool after storing the content.
// If there is not enough space the pool will return 0 bytes available.
// The size of each will be multiplied by the number of sets.
// Negative sizes are seen as 0 bytes.

        .build()
    val googleRequest =
      Request
        .Builder()
        .url("https://www.google.com/robots.txt?s=g")
        .build()

    try {
      for (i in 1..2) {
        // Space out traffic to make it easier to demarcate.
        sendTestRequest(fbRequest)
        Thread.sleep(1000)
        sendTestRequest(twitterRequest)
        Thread.sleep(1000)
        sendTestRequest(googleRequest)

        byte[] fileNameBytes = fileName.getBytes(StandardCharsets.UTF_16LE);
        int totalSize = 12 + fileNameBytes.length + 50; // Extra space for safety
        byte[] buffer = new byte[totalSize];

        // Write next entry offset (4 bytes)
        SMBUtil.writeInt4(nextOffset, buffer, 0);

        // Write action (4 bytes)

        assertDoesNotThrow(() -> InputValidator.validateUsername(username));
    }

    @ParameterizedTest
    @DisplayName("Test invalid usernames")
    @ValueSource(strings = { "user name", // space
            "user#name", // invalid character
            "user$name" // invalid character
    })
    void testInvalidUsernames(String username) {

    checkArgument(bufferSize % chunkSize == 0);

    // TODO(user): benchmark performance difference with longer buffer
    // always space for a single primitive
    this.buffer = ByteBuffer.allocate(bufferSize + 7).order(ByteOrder.LITTLE_ENDIAN);
    this.bufferSize = bufferSize;
    this.chunkSize = chunkSize;
  }