xmltodict和类型判断type、instance

xmltodict 是一个用来处理xml数据的很方便的模块。包含两个常用方法parse和unparse

1. parse

xmltodict.parse()方法可以将xml数据转为python中的dict字典数据：

>>> import xmltodict
>>> xml_str = """
... <xml>
... <ToUserName><![CDATA[gh_866835093fea]]></ToUserName>
... <FromUserName><![CDATA[ogdotwSc_MmEEsJs9-ABZ1QL_4r4]]></FromUserName>
... <CreateTime>1478317060</CreateTime>
... <MsgType><![CDATA[text]]></MsgType>
... <Content><![CDATA[你好]]></Content>
... <MsgId>6349323426230210995</MsgId>
... </xml>
... """
>>>
>>> xml_dict = xmltodict.parse(xml_str)
>>> type(xml_dict)
<class 'collections.OrderedDict'>  # 类字典型，可以按照字典方法操作
>>>
>>> xml_dict
OrderedDict([(u'xml', OrderedDict([(u'ToUserName', u'gh_866835093fea'), (u'FromUserName', u'ogdotwSc_MmEEsJs9-ABZ1QL_4r4'), (u'CreateTime', u'1478317060'), (u'MsgType', u'text'), (u'Content', u'\u4f60\u597d'), (u'MsgId', u'6349323426230210995')]))])
>>>
>>> xml_dict['xml']
OrderedDict([(u'ToUserName', u'gh_866835093fea'), (u'FromUserName', u'ogdotwSc_MmEEsJs9-ABZ1QL_4r4'), (u'CreateTime', u'1478317060'), (u'MsgType', u'text'), (u'Content', u'\u4f60\u597d'), (u'MsgId', u'6349323426230210995')])
>>>
>>> for key, val in xml_dict['xml'].items():
...     print key, "=", val
... 
ToUserName = gh_866835093fea
FromUserName = ogdotwSc_MmEEsJs9-ABZ1QL_4r4
CreateTime = 1478317060
MsgType = text
Content = 你好
MsgId = 6349323426230210995
>>>

2. unparse

xmltodict.unparse()方法可以将字典转换为xml字符串：

xml_dict = {
    "xml": {
        "ToUserName" : "gh_866835093fea",
        "FromUserName" : "ogdotwSc_MmEEsJs9-ABZ1QL_4r4",
        "CreateTime" : "1478317060",
        "MsgType" : "text",
        "Content" : u"你好",
        "MsgId" : "6349323426230210995",
    }
}

>>> xml_str = xmltodict.unparse(xml_dict)
>>> print xml_str
<?xml version="1.0" encoding="utf-8"?>
<xml><FromUserName>ogdotwSc_MmEEsJs9-ABZ1QL_4r4</FromUserName><MsgId>6349323426230210995</MsgId><ToUserName>gh_866835093fea</ToUserName><Content>你好</Content><MsgType>text</MsgType><CreateTime>1478317060</CreateTime></xml>
>>>
>>> xml_str = xmltodict.unparse(xml_dict, pretty=True) # pretty表示友好输出
>>> print xml_str
<?xml version="1.0" encoding="utf-8"?>
<xml>
    <FromUserName>ogdotwSc_MmEEsJs9-ABZ1QL_4r4</FromUserName>
    <MsgId>6349323426230210995</MsgId>
    <ToUserName>gh_866835093fea</ToUserName>
    <Content>你好</Content>
    <MsgType>text</MsgType>
    <CreateTime>1478317060</CreateTime>
</xml>
>>>

3. 类型判断
   Python判断类型，基本类型主要使用type() , 对象类型使用 instance()

print( type(123))
print( type(123) == int)
print( type("hello"))
print( type("hello") == str)
print( type(1.234))
print( type(1.234) == float)
print( type([1,2,3]))
print( type((1,2,3)))
print( type( {"a":1}))
 
 
import types
 
def fun():
  pass
 
print( type(fun))
print( type(fun) == types.FunctionType )
print( type(abs) )
print( type(abs) == types.BuiltinFunctionType )
print( type(lambda x: x) )
print( type(lambda x: x)==types.LambdaType )
print( type((x for x in range(10))) )
print( type((x for x in range(10)))==types.GeneratorType )
 
 
print("--------------------------------")
 
class Animal(object):
    pass
 
class Cat(Animal):
      pass
 
 
class Dog(Animal):
       pass
 
 
a = Animal()
c = Cat()
d = Dog()
 
#  isinstance()判断一个对象是否是某种类型。
 
print(isinstance(a, Animal))
print(isinstance(c, Animal))
print(isinstance(d, Animal))
print(isinstance(c, Cat))
print(isinstance(d, Dog))