is specified via the `role_policy` configuration parameter or the `MINIO_IDENTITY_OPENID_ROLE_POLICY` environment variable. The value is a comma-separated list of IAM access policy names already defined in the server. In this situation, the server prints a role ARN at startup that must be specified as a `RoleArn` API request parameter in the STS AssumeRoleWithWebIdentity API call. When using Role Policies, multiple OpenID providers and/or client applications (with unique client IDs) may be configured...

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

在底层，`open("./somefile.txt")`创建了一个被称为"上下文管理器"的对象。

当 `with` 代码块结束时，它会确保关闭文件，即使发生了异常也是如此。

当你使用 `yield` 创建一个依赖项时，**FastAPI** 会在内部将其转换为上下文管理器，并与其他相关工具结合使用。

### 在使用 `yield` 的依赖项中使用上下文管理器

	defer func() {
		if rinfo.ReplicationStatus == replication.Completed && tgt.ResetID != "" && dobj.OpType == replication.ExistingObjectReplicationType {
			rinfo.ResyncTimestamp = fmt.Sprintf("%s;%s", UTCNow().Format(http.TimeFormat), tgt.ResetID)
		}
	}()

	if dobj.VersionID == "" && rinfo.PrevReplicationStatus == replication.Completed && dobj.OpType != replication.ExistingObjectReplicationType {

```Python hl_lines="2-5  15  21"
{!../../docs_src/handling_errors/tutorial006.py!}
```

errors.invalid_header_for_request_file=Invalid header: {0}
errors.could_not_delete_logged_in_user=Could not delete logged in user.
errors.unauthorized_request=Unauthorized request.
errors.failed_to_print_thread_dump=Failed to print thread dump.
errors.file_is_not_supported={0} is not supported.
errors.plugin_file_is_not_found={0} is not found.
errors.failed_to_install_plugin=Failed to install {0}.

errors.invalid_header_for_request_file=Invalid header: {0}
errors.could_not_delete_logged_in_user=Could not delete logged in user.
errors.unauthorized_request=Unauthorized request.
errors.failed_to_print_thread_dump=Failed to print thread dump.
errors.file_is_not_supported={0} is not supported.
errors.plugin_file_is_not_found={0} is not found.
errors.failed_to_install_plugin=Failed to install {0}.

    (Exception: if the Program itself is interactive but does not
    normally print such an announcement, your work based on the Program
    is not required to print an announcement.)

These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Program, and
can be reasonably considered independent and separate works in

-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...

	}
}

func newXferStats() *XferStats {
	return &XferStats{
		measure: newRateMeasurement(time.Now()),
		sma:     newSMA(50),
	}
}

func (rx *XferStats) String() string {
	return fmt.Sprintf("curr=%f avg=%f, peak=%f", rx.curr(), rx.Avg, rx.Peak)
}

func (rx *XferStats) curr() float64 {
	if rx.measure == nil {
		return 0.0
	}
	return rx.measure.getExpMovingAvgBytesPerSecond()
}

			}
			return written, nil
		}
	}
}

// SafeClose safely closes any channel of any type
func SafeClose[T any](c chan<- T) {
	if c != nil {
		close(c)
		return
	}
	// Print stack to check who is sending `c` as `nil`
	// without crashing the server.
	debug.PrintStack()