解析 YAML 并假设某个路径始终是一个字符串 [英] Parse YAML and assume a certain path is always a string

问题描述

我正在使用来自 http://pyyaml.org 的 YAML 解析器，我希望它始终将某些字段解释为字符串，但我不知道 add_path_resolver() 是如何工作的.

I am using the YAML parser from http://pyyaml.org and I want it to always interpret certain fields as string, but I can't figure out how add_path_resolver() works.

例如:解析器假设version"是一个浮点数:

For example: The parser assumes that "version" is a float:

network:
- name: apple
- name: orange
version: 2.3
site: banana

有些文件有version: 2"(解释为 int)或version: 2.3 alpha"(解释为 str).

Some files have "version: 2" (which is interpreted as an int) or "version: 2.3 alpha" (which is interpreted as a str).

我希望它们总是被解释为 str.

I want them to always be interpreted as a str.

似乎 yaml.add_path_resolver() 应该让我指定，当您看到 version: 时，总是将其解释为 str)但它没有很好地记录.我最好的猜测是:

It seems that yaml.add_path_resolver() should let me specify, "When you see version:, always interpret it as a str) but it is not documented very well. My best guess is:

yaml.add_path_resolver(u'!root', ['version'], kind=str)

但这行不通.

关于如何让我的版本字段始终为字符串的建议?

Suggestions on how to get my version field to always be a string?

附言以下是不同版本"字符串及其解释方式的一些示例:

P.S. Here are some examples of different "version" strings and how they are interpreted:

(Pdb) import yaml
(Pdb) import pprint
(Pdb) pprint.pprint(yaml.load("---\nnetwork:\n- name: apple\n- name: orange\nversion: 2\nsite: banana"))
{'network': [{'name': 'apple'}, {'name': 'orange'}],
 'site': 'banana',
 'version': 2}
(Pdb) pprint.pprint(yaml.load("---\nnetwork:\n- name: apple\n- name: orange\nversion: 2.3\nsite: banana"))
{'network': [{'name': 'apple'}, {'name': 'orange'}],
 'site': 'banana',
 'version': 2.2999999999999998}
(Pdb) pprint.pprint(yaml.load("---\nnetwork:\n- name: apple\n- name: orange\nversion: 2.3 alpha\nsite: banana"))
{'network': [{'name': 'apple'}, {'name': 'orange'}],
 'site': 'banana',
 'version': '2.3 alpha'}

推荐答案

到目前为止，最简单的解决方案不是使用基本的 .load()(无论如何这是不安全的)，而是使用它使用 Loader=BaseLoader，将每个标量作为字符串加载:

By far the easiest solution for this is not use the basic .load() (which is unsafe anyway), but use it with Loader=BaseLoader, which loads every scalar as a string:

import yaml

yaml_str = """\
network:
- name: apple
- name: orange
version: 2.3
old: 2
site: banana
"""

data = yaml.load(yaml_str, Loader=yaml.BaseLoader)
print(data)

给出:

{'network': [{'name': 'apple'}, {'name': 'orange'}], 'version': '2.3', 'old': '2', 'site': 'banana'}

这篇关于解析 YAML 并假设某个路径始终是一个字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！