FastAPI从入门到实战（14）——带yield的依赖

from fastapi import APIRouter, Depends

app14 = APIRouter()

"""Dependencies with yield 带yield的依赖"""


# 这个需要Python3.7才支持，Python3.6需要pip install async-exit-stack async-generator
# 以下都是伪代码

async def get_db():
    db = "db_connection"
    try:
        yield db
    finally:
        db.endswith("db_close")


async def dependency_a():
    dep_a = "generate_dep_a()"
    try:
        yield dep_a
    finally:
        dep_a.endswith("db_close")


async def dependency_b(dep_a=Depends(dependency_a)):
    dep_b = "generate_dep_b()"
    try:
        yield dep_b
    finally:
        dep_b.endswith(dep_a)


async def dependency_c(dep_b=Depends(dependency_b)):
    dep_c = "generate_dep_c()"
    try:
        yield dep_c
    finally:
        dep_c.endswith(dep_b)