YAML+PyYAML笔记 7 | PyYAML源码之yaml.compose_all()，yaml.load(),yaml.load_all()

1 yaml.compose_all()

• 源码：
  
• 作用：分析流中的所有YAML文档，并产生相应的表示树。
• 解析：

# -*- coding:utf-8 -*-
# 作者：虫无涯
# 日期：2023/7/28 
# 文件名称：pyyaml_compose_all.py
# 作用：yaml.compose_all()
# 联系：VX(NoamaNelson)
# 博客：https://blog.csdn.net/NoamaNelson

import yaml

doc = """
---
user1:
  name: xiaoming
  age: 23
  password: 123456
---
user2:
  name: xiaozhang
  age: 24
  password: 123456
---
user3:
  name: xiaoli
  age: 25
  password: 123456
"""

trees = yaml.compose_all(doc)
for tree in trees:
    print(tree)

• 输出：

MappingNode(tag='tag:yaml.org,2002:map', value=[(ScalarNode(tag='tag:yaml.org,2002:str', value='user1'), MappingNode(tag='tag:yaml.org,2002:map', value=[(ScalarNode(tag='tag:yaml.org,2002:str', value='name'), ScalarNode(tag='tag:yaml.org,2002:str', value='xiaoming')), (ScalarNode(tag='tag:yaml.org,2002:str', value='age'), ScalarNode(tag='tag:yaml.org,2002:int', value='23')), (ScalarNode(tag='tag:yaml.org,2002:str', value='password'), ScalarNode(tag='tag:yaml.org,2002:int', value='123456'))]))])
MappingNode(tag='tag:yaml.org,2002:map', value=[(ScalarNode(tag='tag:yaml.org,2002:str', value='user2'), MappingNode(tag='tag:yaml.org,2002:map', value=[(ScalarNode(tag='tag:yaml.org,2002:str', value='name'), ScalarNode(tag='tag:yaml.org,2002:str', value='xiaozhang')), (ScalarNode(tag='tag:yaml.org,2002:str', value='age'), ScalarNode(tag='tag:yaml.org,2002:int', value='24')), (ScalarNode(tag='tag:yaml.org,2002:str', value='password'), ScalarNode(tag='tag:yaml.org,2002:int', value='123456'))]))])
MappingNode(tag='tag:yaml.org,2002:map', value=[(ScalarNode(tag='tag:yaml.org,2002:str', value='user3'), MappingNode(tag='tag:yaml.org,2002:map', value=[(ScalarNode(tag='tag:yaml.org,2002:str', value='name'), ScalarNode(tag='tag:yaml.org,2002:str', value='xiaoli')), (ScalarNode(tag='tag:yaml.org,2002:str', value='age'), ScalarNode(tag='tag:yaml.org,2002:int', value='25')), (ScalarNode(tag='tag:yaml.org,2002:str', value='password'), ScalarNode(tag='tag:yaml.org,2002:int', value='123456'))]))])

2 yaml.load()

• 源码：
  

• 作用：解析流中的第一个YAML文档，并生成相应的Python对象；

• 解析：

# config_pyyaml.yaml如下：

user1:
  name: xiaoming
  age: 23
  password: 123456
user2:
  name: xiaozhang
  age: 24
  password: 123456
user3:
  name: xiaoli
  age: 25
  password: 123456

# pyyaml_load.py如下：

# -*- coding:utf-8 -*-
# 作者：虫无涯
# 日期：2023/7/28 
# 文件名称：pyyaml_load.py
# 作用：yaml.load()
# 联系：VX(NoamaNelson)
# 博客：https://blog.csdn.net/NoamaNelson

import yaml

with open('config_pyyaml.yaml', 'r') as f:
    data = yaml.load(f, Loader=yaml.FullLoader)

print(data)

• 输出：

{
    
    'user1': {
    
    'name': 'xiaoming', 'age': 23, 'password': 123456}, 'user2': {
    
    'name': 'xiaozhang', 'age': 24, 'password': 123456}, 'user3': {
    
    'name': 'xiaoli', 'age': 25, 'password': 123456}}

3 yaml.load_all()

• 源码：
  
• 作用：解析流中的所有YAML文档并生成相应的Python对象；
• 解析：

# config_pyyaml01.yaml如下：

---
user1:
  name: xiaoming
  age: 23
  password: 123456
---
user2:
  name: xiaozhang
  age: 24
  password: 123456
---
user3:
  name: xiaoli
  age: 25
  password: 123456

# pyyaml_load_all.py如下：

# -*- coding:utf-8 -*-
# 作者：虫无涯
# 日期：2023/7/28 
# 文件名称：pyyaml_load_all.py
# 作用：yaml.load_all()
# 联系：VX(NoamaNelson)
# 博客：https://blog.csdn.net/NoamaNelson

import yaml

f = open('config_pyyaml01.yaml', 'r')
docs = yaml.load_all(f, Loader=yaml.FullLoader)
for doc in docs:
    print(doc)
f.close()

• 输出：

{
    
    'user1': {
    
    'name': 'xiaoming', 'age': 23, 'password': 123456}}
{
    
    'user2': {
    
    'name': 'xiaozhang', 'age': 24, 'password': 123456}}
{
    
    'user3': {
    
    'name': 'xiaoli', 'age': 25, 'password': 123456}}