pyyaml模块

pyyaml模块是一种文件数据处理格式的方法，常用与生成、解析或修改.yaml配置文件

　　1.常见.yaml文件格式内容如下

languages:
 - Ruby
 - Perl
 - Python 
websites:
 YAML: yaml.org 
 Ruby: ruby-lang.org 
 Python: python.org 
 Perl: use.perl.org 

　　2.pyyaml模块的简单使用

# -*- coding:utf-8 -*-
# Author:Wong Du

'''
以下是pyyaml模块的简单用法，
详细请见：https://pyyaml.org/wiki/PyYAMLDocumentation
'''

import yaml

### Part1
print(yaml.load("""
- wong
- dudu
- caiyun
"""))
# 效果：['wong', 'dudu', 'caiyun']


### Part2
a = yaml.load("""
name: 
 wong:
  age: 
   24
 dudu: 
  age: 
   23
""")
print(a)
# 效果：{'name': {'dudu': {'age': 23}, 'wong': {'age': 24}}}


### Part3
# '---'作为分隔符分隔多个字典，加载documents内的三个dict
documents = """
---
name: The Set of Gauntlets 'Pauraegen'
description: 
 A set of handgear with sparks that crackle
  across its knuckleguards.
---
name: The Set of Gauntlets 'Paurnen'
description: 
  A set of gauntlets that gives off a foul,
  acrid odour yet remains untarnished.
---
name: The Set of Gauntlets 'Paurnimmen'
description: 
  A set of handgear, freezing with unnatural cold.
"""
# 解析多个字典，要用load_all，解析documents内容生成一个生成器
b = yaml.load_all(documents)
b_data_list = []
for data in b:
    print(data)
    b_data_list.append(data)
'''
效果：
    {'name': "The Set of Gauntlets 'Pauraegen'", 'description': 'A set of handgear with sparks that crackle across its knuckleguards.'}
    {'name': "The Set of Gauntlets 'Paurnen'", 'description': 'A set of gauntlets that gives off a foul, acrid odour yet remains untarnished.'}
    {'name': "The Set of Gauntlets 'Paurnimmen'", 'description': 'A set of handgear, freezing with unnatural cold.'}
'''


### Part4
# 将多个字典转成字符串要用dump_all，生成yaml文档格式数据
c = yaml.dump_all(b_data_list, default_flow_style=False)
print(c)
with open('document.yaml', 'w') as f:
    f.write(c)      # 写入

# 解析文件中的数据
with open('document.yaml') as f:
    d = yaml.load_all(f.read())     # 读取加载
print(d)    # 生成器内存地址
for i in d:
    print(i)


### Part5 文档格式有不同表示方法，解析后效果相同
sum = """
a: 1
b:
 c: 3
 d: 4
"""
print(yaml.dump(yaml.load(sum)))
'''
效果：
    a: 1
    b: {c: 3, d: 4}
'''
print(yaml.dump(yaml.load(sum), default_flow_style=False))
'''
效果：
    a: 1
    b:
      c: 3
      d: 4
'''

　　3.pyyaml模块解析文件小实例

apache:
  pkg.installed: []
  service.running:
    - reload: True
    - watch:
      - file: /etc/httpd/conf/httpd.conf
  user.present:
    - uid: 87
    - gid: 87
    - home: /var/www/html
    - shell: /bin/nologin
    - require:
      - group: apache
  group.present:
    - gid: 87
    - require:
      - pkg: apache

/etc/httpd/conf/httpd.conf:
  file.managed:
    - source: salt://apache/httpd.conf
    - user: root
    - group: root
    - mode: 644

---
test:
  - hostname
  - ipaddr
  - port
  - operator

# -*- coding:utf-8 -*-
# Author: Wongdu

import yaml
import os

def host_parser():
    path_file = 'host.yaml'
    data_list = []
    if os.path.isfile(path_file):
        with open(path_file) as f:
            host_data = yaml.load_all(f.read())
        for item in host_data:
            data_list.append(item)
        if len(data_list) > 1:
            data = data_list
        else:
            data = data_list[0]

        return data
    else:
        exit("%s is not a valid yaml config file.." % path_file)

data = host_parser()
print(data)