////

## 在 Python 中讀取環境變數

你也可以在 Python **之外**的終端機中建立環境變數（或使用其他方法），然後在 Python 中**讀取**它們。

例如，你可以建立一個名為 `main.py` 的檔案，其中包含以下內容：

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

第二個參數是 <a href="https://docs.python.org/zh-tw/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 的預設回傳值。

		if strings.HasPrefix(line, "GLOBL ") {
			continue
		}

		// The general form of a test input line is:
		//	// comment
		//	INST args [// printed form] [// hex encoding]
		parts := strings.Split(line, "//")
		printed := strings.TrimSpace(parts[0])
		if printed == "" || strings.HasSuffix(printed, ":") { // empty or label
			continue
		}
		seq++

		var hexes string
		switch len(parts) {
		default:

-flexbox!important;display:inline-flex!important}}@media print{.d-print-none{display:none!important}.d-print-inline{display:inline!important}.d-print-inline-block{display:inline-block!important}.d-print-block{display:block!important}.d-print-table{display:table!important}.d-print-table-row{display:table-row!important}.d-print-table-cell{display:table-cell!important}.d-print-flex{display:-ms-flexbox!important;display:flex!important}.d-print-inline-flex{display:-ms-inline-flexbox!important;display...

      subsequently incorporated within the Work.

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      copyright license to reproduce, prepare Derivative Works of,
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      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the

      subsequently incorporated within the Work.

   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the

      subsequently incorporated within the Work.

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      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the

      subsequently incorporated within the Work.

   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
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