Ruby列印或從物件回傳特定欄位

如何group_id從回傳的物件列印？

以下是從函式回傳的。我想列印group_id或者回傳group_id

 {
  :security_groups=>[
    {
      :description=>"Created By ManageIQ",
      :group_name=>"MIQ_019",
      :ip_permissions=>[
        {
          :from_port=>22,
          :ip_protocol=>"tcp",
          :ip_ranges=>[
            {
              :cidr_ip=>"0.0.0.0/0",
              :description=>nil
            }
          ],
          :ipv_6_ranges=>[],
          :prefix_list_ids=>[],
          :to_port=>22,
          :user_id_group_pairs=>[]
        }
      ],
      :owner_id=>"943755119718",
      :group_id=>"sg-0c2c5f219f1bafc1a",
      :ip_permissions_egress=>[
        {
          :from_port=>nil,
          :ip_protocol=>"-1",
          :ip_ranges=>[
            {
              :cidr_ip=>"0.0.0.0/0",
              :description=>nil
            }
          ],
          :ipv_6_ranges=>[],
          :prefix_list_ids=>[],
          :to_port=>nil,
          :user_id_group_pairs=>[]
        }
      ],
      :tags=>[],
      :vpc_id=>"vpc-d817c1b3"
    }
  ],
  :next_token=>nil
}

這是功能：我想要return security_group.group_id

def describe_security_group (
  group_name
 )  
  ec2 = get_aws_client
  security_group = ec2.describe_security_groups(
    filters: [
      {name: 'group-name', values: [ group_name ]}]
    )
  puts "Describing security group '#{group_name}' with ID " \
    "'#{security_group}'"
  return security_group
rescue StandardError => e
  puts "Error describing security group: #{e.message}"  
  return 
end

uj5u.com熱心網友回復：

所以，回傳值看起來像一個散列，或者你可以讓它完全散列。

對于單元素陣列的情況，您可以簡單地使用 ruby?? dig方法。

根據您的資料和下面的評論，我們可以像這樣訪問所需的元素：

# from your ec2 api call
security_group  = ec2.describe_security_groups(...)

# Result value is stored in `security_group` variable,
# and looks exactly like hash below
{
  :security_groups=>[
    {
      :description=>"Created By ManageIQ",
      :group_name=>"MIQ_019",
      :ip_permissions=>[
        {
          :from_port=>22,
          :ip_protocol=>"tcp",
          :ip_ranges=>[
            {
              :cidr_ip=>"0.0.0.0/0",
              :description=>nil
            }
          ],
          :ipv_6_ranges=>[],
          :prefix_list_ids=>[],
          :to_port=>22,
          :user_id_group_pairs=>[]
        }
      ],
      :owner_id=>"943755119718",
      :group_id=>"sg-0c2c5f219f1bafc1a",
      :ip_permissions_egress=>[
        {
          :from_port=>nil,
          :ip_protocol=>"-1",
          :ip_ranges=>[
            {
              :cidr_ip=>"0.0.0.0/0",
              :description=>nil
            }
          ],
          :ipv_6_ranges=>[],
          :prefix_list_ids=>[],
          :to_port=>nil,
          :user_id_group_pairs=>[]
        }
      ],
      :tags=>[],
      :vpc_id=>"vpc-d817c1b3"
    }
  ],
  :next_token=>nil
}

# And this is a target value, that you can store in another one,
# return from method or simply print to output
security_group.dig(:security_groups)
              .try(:[], 0)
              .dig(:group_id)

=> "sg-0c2c5f219f1bafc1a"

但是，如果您需要在包含多個元素的陣列中搜索，來自Ruby 的 Enumerable 模塊的方法可能會有所幫助（例如select或reject）。

使用OpenStruct進行更新，如果您更喜歡使用點表示法的此類方法呼叫：

json = security_group.to_json

os = JSON.parse(json, object_class: OpenStruct)

os.security_groups.first.group_id
=> "sg-0c2c5f219f1bafc1a"

標籤：红宝石

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