# Bigger Applications - Multiple Files

If you are building an application or a web API, it's rarely the case that you can put everything on a single file.

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

!!! info
    If you come from Flask, this would be the equivalent of Flask's Blueprints.

## An example file structure

Let's say you have a file structure like this:

```
.
├── app

* 📤 📁 `app/internal/` ⏮️ ➕1️⃣ 📁 `__init__.py`, ⚫️ ➕1️⃣ "🐍 📦": `app.internal`.
*  & 📁 `app/internal/admin.py` ➕1️⃣ 🔁: `app.internal.admin`.

<img src="/img/tutorial/bigger-applications/package.svg">

🎏 📁 📊 ⏮️ 🏤:

```
.
├── app                  # "app" is a Python package
│   ├── __init__.py      # this file makes "app" a "Python package"

* 还有一个子目录 `app/internal/` 包含另一个 `__init__.py` 文件，因此它是又一个「Python 子包」：`app.internal`。
* `app/internal/admin.py` 是另一个子模块：`app.internal.admin`。

<img src="https://fastapi.tiangolo.com/img/tutorial/bigger-applications/package.svg">

带有注释的同一文件结构：

```
.
├── app                  # 「app」是一个 Python 包
│   ├── __init__.py      # 这个文件使「app」成为一个 Python 包
│   ├── main.py          # 「main」模块，例如 import app.main

			if err != nil {
				return nil, err
			}
			todo -= primes[i].BitLen()
		}

		// Make sure that primes is pairwise unequal.
		for i, prime := range primes {
			for j := 0; j < i; j++ {
				if prime.Cmp(primes[j]) == 0 {
					continue NextSetOfPrimes
				}
			}
		}

		n := new(big.Int).Set(bigOne)
		totient := new(big.Int).Set(bigOne)
		pminus1 := new(big.Int)
		for _, prime := range primes {

	var val, pos int
	var digLen int // number of digits in current octet
	s := in[off:end]
	for i := 0; i < len(s); i++ {
		if s[i] >= '0' && s[i] <= '9' {
			if digLen == 1 && val == 0 {
				return parseAddrError{in: in, msg: "IPv4 field has octet with leading zero"}
			}
			val = val*10 + int(s[i]) - '0'
			digLen++
			if val > 255 {

		argLen: 0,
		reg:    regInfo{},
	},
	{
		name:   "FlagGT_UGT",
		argLen: 0,
		reg:    regInfo{},
	},
	{
		name:   "FlagGT_ULT",
		argLen: 0,
		reg:    regInfo{},
	},
	{
		name:    "MOVSSconst1",
		auxType: auxFloat32,
		argLen:  0,
		reg: regInfo{
			outputs: []outputInfo{
				{0, 239}, // AX CX DX BX BP SI DI
			},
		},
	},
	{

	// signatures will come out different from other architectures, which will
	// break TLS recorded tests.
	for {
		N := c.Params().N
		b := make([]byte, (N.BitLen()+7)/8)
		if _, err = io.ReadFull(rand, b); err != nil {
			return
		}
		if excess := len(b)*8 - N.BitLen(); excess > 0 {
			b[0] >>= excess
		}
		k = new(big.Int).SetBytes(b)
		if k.Sign() != 0 && k.Cmp(N) < 0 {
			return
		}
	}

		got[strings.TrimPrefix(string(match), " can inline ")] = true
		return nil
	})
	wantInlinable := []string{
		"(*uint128).halves",
		"Addr.BitLen",
		"Addr.hasZone",
		"Addr.Is4",
		"Addr.Is4In6",
		"Addr.Is6",
		"Addr.IsInterfaceLocalMulticast",
		"Addr.IsValid",
		"Addr.IsUnspecified",
		"Addr.Less",
		"Addr.Unmap",
		"Addr.Zone",
		"Addr.v4",

func (k *PrivateKey) ECDH() (*ecdh.PrivateKey, error) {
	c := curveToECDH(k.Curve)
	if c == nil {
		return nil, errors.New("ecdsa: unsupported curve by crypto/ecdh")
	}
	size := (k.Curve.Params().N.BitLen() + 7) / 8
	if k.D.BitLen() > size*8 {
		return nil, errors.New("ecdsa: invalid private key")
	}
	return c.NewPrivateKey(k.D.FillBytes(make([]byte, size)))
}

func curveToECDH(c elliptic.Curve) ecdh.Curve {
	switch c {

flatbuffer_cc_library(
    name = "schema_fbs_with_mutable",
    srcs = ["schema.fbs"],
    compatible_with = get_compatible_with_portable(),
    flatc_args = [
        "--gen-mutable",
        "--gen-object-api",
    ],
    out_prefix = "mutable/",
)

# Generic schema for inference on device (but with reflections makes bigger).
flatbuffer_cc_library(