YAMLparsing和Python？
将YAML文件parsing为Python对象的最佳方法是什么？
例如，这个YAML：
Person: name: XYZ 到这个Python类：
class Person(yaml.YAMLObject): yaml_tag = 'Person' def __init__(self, name): self.name = name
顺便说一句，我正在使用PyYAML。
如果你的YAML文件如下所示：
# tree format treeroot: branch1: name: Node 1 branch1-1: name: Node 1-1 branch2: name: Node 2 branch2-1: name: Node 2-1
你已经安装了PyYAML ：
pip install PyYAML
Python代码如下所示：
import yaml with open('tree.yaml') as f: # use safe_load instead load dataMap = yaml.safe_load(f)
variablesdataMap现在包含一个包含树数据的字典。 如果你用PrettyPrint打印dataMap ，你会得到如下的东西：
{'treeroot': {'branch1': {'branch1-1': {'name': 'Node 1-1'}, 'name': 'Node 1'}, 'branch2': {'branch2-1': {'name': 'Node 2-1'}, 'name': 'Node 2'}}}
所以，现在我们已经看到了如何将数据导入到我们的Python程序中。 保存数据同样简单：
with open('newtree.yaml', "w") as f: yaml.dump(dataMap, f)
你有一个字典，现在你必须把它转换成一个Python对象：
class Struct: def __init__(self, **entries): self.__dict__.update(entries)
那么你可以使用：
>>> args = your YAML dictionary >>> s = Struct(**args) >>> s <__main__.Struct instance at 0x01D6A738> >>> s...
并按照“ 将Python字典转换为对象 ”。
欲了解更多信息，你可以看看pyyaml.org和这个 。
从http://pyyaml.org/wiki/PYYAMLDocumentation ：
add_path_resolver(tag, path, kind)添加了一个基于path的隐式标签parsing器。 path是在表示graphics中形成节点path的关键字列表。 path元素可以是string值，整数或无。 节点的种类可以是str，list，dict或None。
#!/usr/bin/env python import yaml class Person(yaml.YAMLObject): yaml_tag = '!person' def __init__(self, name): self.name = name yaml.add_path_resolver('!person', ['Person'], dict) data = yaml.load(""" Person: name: XYZ """) print data # {'Person': <__main__.Person object at 0x7f2b251ceb10>} print data['Person'].name # XYZ
这里有一种方法来testing用户在virtualenv（或系统）上select了哪个YAML实现，然后适当地定义load_yaml_file ：
load_yaml_file = None if not load_yaml_file: try: import yaml load_yaml_file = lambda fn: yaml.load(open(fn)) except: pass if not load_yaml_file: import commands, json if commands.getstatusoutput('ruby --version')[0] == 0: def load_yaml_file(fn): ruby = "puts YAML.load_file('%s').to_json" % fn j = commands.getstatusoutput('ruby -ryaml -rjson -e "%s"' % ruby) return json.loads(j[1]) if not load_yaml_file: import os, sys print """ ERROR: %s requires ruby or python-yaml to be installed. apt-get install ruby OR apt-get install python-yaml OR Demonstrate your mastery of Python by using pip. Please research the latest pip-based install steps for python-yaml. Usually something like this works: apt-get install epel-release apt-get install python-pip apt-get install libyaml-cpp-dev python2.7 /usr/bin/pip install pyyaml Notes: Non-base library (yaml) should never be installed outside a virtualenv. "pip install" is permanent: https://stackoverflow.com/questions/1550226/python-setup-py-uninstall Beware when using pip within an aptitude or RPM script. Pip might not play by all the rules. Your installation may be permanent. Ruby is 7X faster at loading large YAML files. pip could ruin your life. https://stackoverflow.com/questions/46326059/ https://stackoverflow.com/questions/36410756/ https://stackoverflow.com/questions/8022240/ Never use PyYaml in numerical applications. https://stackoverflow.com/questions/30458977/ If you are working for a Fortune 500 company, your choices are 1. Ask for either the "ruby" package or the "python-yaml" package. Asking for Ruby is more likely to get a fast answer. 2. Work in a VM. I highly recommend Vagrant for setting it up. """ % sys.argv[0] os._exit(4) # test import sys print load_yaml_file(sys.argv[1])
