以特定格式将元组转储到 YAML 文件中

Question

我有一个特定的格式，我想将元组转储到 YAML 文件中。我有以下代码，我已经尝试运行将元组转储到 YAML 文件中。从下面的代码中，我尝试使用 append() 将一对元组 (x, y) 添加到列表中。之后，我会将列表转储回 YAML 文件中。我的问题是，当我转储回 YAML 文件时，我是否可以保留文件的相同特定格式？

import ruamel.yaml

def addObstacles():

    yaml = ruamel.yaml.YAML()
    with open('input.yaml') as f:
        doc = yaml.load(f)

    x = 5
    y = 6
    doc['map']['obstacles'].append(list((x,y)))

    with open('input.yaml', 'w') as f:
        yaml.dump(doc, f)

以下文件的输出结果如下：

map:
  dimensions: [8, 8]
  obstacles:
  - !!python/tuple [4, 5]
  - !!python/tuple [2, 0]
  - !!python/tuple [1, 1]
  - !!python/tuple [0, 5]
  - !!python/tuple [2, 5]
  - !!python/tuple [4, 4]
  - !!python/tuple [7, 5]
  - !!python/tuple [1, 4]
  - !!python/tuple [6, 7]
  - !!python/tuple [6, 3]
  - !!python/tuple [1, 7]
  - !!python/tuple [3, 6]
  - - 5
    - 6

文件的预期输出如下：

map:
  dimensions: [8, 8]
  obstacles:
  - !!python/tuple [4, 5]
  - !!python/tuple [2, 0]
  - !!python/tuple [1, 1]
  - !!python/tuple [0, 5]
  - !!python/tuple [2, 5]
  - !!python/tuple [4, 4]
  - !!python/tuple [7, 5]
  - !!python/tuple [1, 4]
  - !!python/tuple [6, 7]
  - !!python/tuple [6, 3]
  - !!python/tuple [1, 7]
  - !!python/tuple [3, 6]
  - !!python/tuple [5, 6]

Answer 1

我不确定你是否真的需要 ruamel.yaml。 PyYAML 开箱即用：

import yaml

def addObstacles():
    with open('in.yaml') as f:
        doc = yaml.load(f)

    doc['map']['obstacles'].append((5, 6))

    with open('out.yaml', 'w') as f:
        yaml.dump(doc, f)

Answer 2

既然你追加了一个列表，你就会得到一个列表，但我假设你试过了，因为一个普通的元组会不起作用，因为您实际上在 ruamel.yaml.

中发现了一个错误

这可以通过两行代码轻松解决，并通过指定 default_flow_style:

import sys
import ruamel.yaml

if ruamel.yaml.version_info < (0, 16, 7):
   ruamel.yaml.representer.RoundTripRepresenter.add_representer(tuple, 
                         ruamel.yaml.representer.Representer.represent_tuple)

def addObstacles():

    yaml = ruamel.yaml.YAML()
    yaml.default_flow_style = None   # default is False, which would get you a block sequence
    with open('input.yaml') as f:
        doc = yaml.load(f)
    doc['map']['obstacles'].append((5, 6))

    yaml.dump(doc, sys.stdout)


addObstacles()

这样你就能得到你想要的：

map:
  dimensions: [8, 8]
  obstacles:
  - !!python/tuple [4, 5]
  - !!python/tuple [2, 0]
  - !!python/tuple [1, 1]
  - !!python/tuple [0, 5]
  - !!python/tuple [2, 5]
  - !!python/tuple [4, 4]
  - !!python/tuple [7, 5]
  - !!python/tuple [1, 4]
  - !!python/tuple [6, 7]
  - !!python/tuple [6, 3]
  - !!python/tuple [1, 7]
  - !!python/tuple [3, 6]   # add one after this
  - !!python/tuple [5, 6]

（我在我使用的 YAML 输入文件中添加了注释）。

以特定格式将元组转储到 YAML 文件中

Dump tuple into YAML file in a specific format

python

yaml

ruamel.yaml