rsonlite 0.1.0

摘要

rsonlite 是在Python中创建自定义缩进数据文件格式的最简单方法。它是一个可以与您的应用程序一起分发的单个小型模块，也可以轻松安装或从PyPI安装。

背景

rson项目 包含一个解析器，允许对可读文件格式的变体进行实验，并定义了一个基RSON配置文件，它是JSON的严格超集（正确地子类化，RSON解析器通过了Python simplejson测试套件，它本身是JSON的超集）。

RSON是在对当时可用的纯Python YAML解析器的大小和速度感到沮丧后诞生的，并且与YAML有着非常相似的目标 - 这些格式的一个关键特点是使用缩进来作为语法，尽可能去除不必要的语法元素，如引号，以及添加注释和使用JSON作为有效输入的能力。

基本RSON格式定义是为了便于从任何语言中进行解析而设计的，但Python解析器本身既灵活又快速，使得可以轻松设计并测试变体格式。其中一种格式是能够轻松与XML双向转换的格式，另一种格式允许宏和包含处理。

但这种灵活性是有代价的。代码更多，所有选项的学习曲线都比如果解析器不那么灵活时要陡峭，而文档——嗯，要正确地记录所有选项需要很长时间，所以还没有完成。

rsonlite是rson的简化版本，主要处理缩进语义，允许客户端代码进行高级解析。与区分“true”、“false”、“null”、字符串和数字的JSON或基本RSON不同，或者simplejson添加了“Nan”和“Infinity”，rsonlite将世界划分为容器节点和叶节点，每个叶节点都是一个字符串。

介绍

rsonlite是一个Python库，它使得使用缩进来构建声明性分层数据结构的文件解析器变得容易。（仅考虑空格——制表符不被视为缩进。）

示例

我从JSON示例页面那里无耻地借鉴了这些示例的大部分，因为JSON是对比和对比rsonlite的绝佳事物。

示例1

>>> import rsonlite
>>> jsonstr1 = '''
... {
...     "glossary": {
...         "title": "example glossary",
...         "GlossDiv": {
...             "title": "S",
...             "GlossList": {
...                 "GlossEntry": {
...                     "ID": "SGML",
...                     "SortAs": "SGML",
...                     "GlossTerm": "Standard Generalized Markup Language",
...                     "Acronym": "SGML",
...                     "Abbrev": "ISO 8879:1986",
...                     "GlossDef": {
...                         "para": "A meta-markup language",
...                         "GlossSeeAlso": ["GML", "XML"]
...                     },
...                     "GlossSee": "markup"
...                 }
...             }
...         }
...     }
... }
... '''
>>>
>>> rsonstr1 = '''
...     glossary
...         title = example glossary
...         GlossDiv
...             title = S
...             GlossList
...                 GlossEntry
...                     ID = SGML
...                     SortAs = SGML
...                     GlossTerm = Standard Generalized Markup Language
...                     Acronym = SGML
...                     Abbrev = ISO 8879:1986
...                     GlossDef
...                         para = A meta-markup language
...                         GlossSeeAlso = [GML, XML]
...                     GlossSee = markup
... '''
>>>
>>> jsondata1 = eval(jsonstr1)
>>> rsondata1 = rsonlite.simpleparse(rsonstr1)
>>> jsondata1 == rsondata1
True

示例2

>>> jsonstr2 = '''
... {"menu": {
...     "id": "file",
...     "value": "File",
...     "popup": {
...         "menuitem": [
...         {"value": "New", "onclick": "CreateNewDoc()"},
...         {"value": "Open", "onclick": "OpenDoc()"},
...         {"value": "Close", "onclick": "CloseDoc()"}
...         ]
...     }
... }}
... '''
>>>
>>> rsonstr2 = '''
...     menu
...         id = file
...         value = File
...         popup
...             menuitem
...                 value = New
...                 onclick = CreateNewDoc()
...                 value = Open
...                 onclick = OpenDoc()
...                 value = Close
...                 onclick = CloseDoc()
... '''
>>>
>>> jsondata2 = eval(jsonstr2)
>>> rsondata2 = rsonlite.simpleparse(rsonstr2)
>>> jsondata2 == rsondata2
True

API

>>> rsondata1 = rsonlite.loads(rsonstr1)
>>> roundtrip = rsonlite.dumps(rsondata1, initial_indent='    ')
>>> roundtrip == rsonstr1[1:]    # Get past initial \n
True

>>> rsondata2 = rsonlite.loads(rsonstr2)
>>> roundtrip = rsonlite.dumps(rsondata2, initial_indent='    ')
>>> roundtrip == rsonstr2[1:]    # Get past initial \n
True

>>> data = rsonlite.loads(rsonstr2)
>>> pretty = rsonlite.pretty(data)
>>> print pretty,
[
    ('menu', [
        ('id', ['file']),
        ('value', ['File']),
        ('popup', [
            ('menuitem', [
                ('value', ['New']),
                ('onclick', ['CreateNewDoc()']),
                ('value', ['Open']),
                ('onclick', ['OpenDoc()']),
                ('value', ['Close']),
                ('onclick', ['CloseDoc()']),
            ])
        ])
    ])
]
>>> eval(pretty) == data
True
>>>

测试

空输入

>>> rsonlite.loads('') == rsonlite.loads('   \n \n     \n') == []
True

错误的缩进

>>> rsonlite.loads('a\n    b\n  c')
Traceback (most recent call last):
  File "<doctest README.txt[22]>", line 1, in <module>
    rsonlite.loads('a\n    b\n  c')
  File "/home/pat/projects/opensource/rson/lite/rsonlite.py", line 179, in loads
    raise err
IndentationError: unindent does not match any outer indentation level (<rsonlite>, line 3)

多行数据，包含特殊字符

>>> teststr = '''
...     My key =
...            This is indented #=
...       This should be at the left edge ===#
...           This is indented differently
... '''
>>> test2 = '\n'.join(x[6:] for x in teststr.splitlines()[2:])
>>> rsonlite.loads(teststr) == [('My key', [test2])]
True

>>> teststr = '''
...     My key =  Something on the first line is at the left edge
...            This is indented
...       This should be at the left edge
...           This is indented differently
... '''
>>> test2 = teststr.split('=', 1)[1].strip().splitlines()
>>> for i in range(1, len(test2)):
...   test2[i] = test2[i][6:]
>>> test2 = '\n'.join(test2)
>>> rsonlite.loads(teststr) == [('My key', [test2])]
True

注释和特殊字符串内容

>>> test1 = '''
...   a
...      b = 1
...       This is part of b's string
...      c
...   d = 2
... '''
>>> test2 = '''
... # Comments can start anywhere outside a string
...   a   # Like here  (but not below)
...      b = 1
...       This is part of b's string
...      # This isn't in the string because it's far enough left
...      # Any non-key string can start with '='
...      = c
...      # This isn't in the string because it's far enough left
...   d = 2
... '''
>>> rsonlite.loads(test1) == rsonlite.loads(test2)
True