# 第一步

最簡單的 FastAPI 檔案可能看起來像這樣：

{* ../../docs_src/first_steps/tutorial001.py *}

將其複製到一個名為 `main.py` 的文件中。

執行即時重新載入伺服器（live server）：

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

        testData.clear();
        testData.add(createRelatedContent("test", "Updated Content", ""));
        mockBhv.setTestData(testData);

        relatedContentHelper.update();
        // Give a moment for async execution
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            // ignore
        }

	if lens == 0 {
		// If the number is 0, it means there are no statements stored in the LRU cache.
		// The test fails and an error message is output.
		t.Fatalf("lru should not be empty")
	}
	// Wait for 40 seconds to give the statements in the cache enough time to expire.
	time.Sleep(time.Second * 40)
	// Assert whether the connection pool of tx is successfully converted to the *gorm.PreparedStmtDB type.
	AssertEqual(t, ok, true)

    val key = key(request.url)
    val snapshot: DiskLruCache.Snapshot =
      try {
        cache[key] ?: return null
      } catch (_: IOException) {
        return null // Give up because the cache cannot be read.
      }

    val entry: Entry =
      try {
        Entry(snapshot.getSource(ENTRY_METADATA))
      } catch (_: IOException) {
        snapshot.closeQuietly()

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      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

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      modifications, and in Source or Object form, provided that You
      meet the following conditions:

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          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

# First Steps { #first-steps }

The simplest FastAPI file could look like this:

{* ../../docs_src/first_steps/tutorial001.py *}

Copy that to a file `main.py`.

Run the live server:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:solid">main.py</u>

  <span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting development server 🚀

# ----------------------------------------------------------
# Application Exception
# ---------------------
# /- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# five framework-embedded messages (don't change key names)
# - - - - - - - - - -/
errors.login.failure = Anmeldung fehlgeschlagen.
errors.app.illegal.transition = Ungültiger Übergang. Bitte versuchen Sie es erneut.