lxml-mate 0.5.3

The simplest Object-XML mapper for Python. Mate for lxml.

What is lxml-mate?

The simplest XML-Object mapper for Python powered by lxml. It’s powerful.

No class definitions are needed to define structure of your XML document.

You can create a brand new xml, or create from string, xml document and handle it in very pythonic way.

See source code for more documents.

Features

Intercept AttributeError when access a non-existent tag in order to access more easily.

For exmaple:

>>> s = '''
...    <root>
...        <person height='180cm'>
...            <name>jack</name>
...            <age>18</age>
...        </person>
...        <person>
...            <name>peter</name>
...        </person>
...    </root>
>>>    '''

when we access the second person’s age, lxml.objectify.ObjectifiedElement will raise an AttributeError. lxml-mate will create an null node instead of raising an exception.

lxml:

>>> r = objectify.fromstring( s )
>>> ages = [ ( p.name, p.age ) for p in r.person ] #AttributeError be raised.
>>> r.person[0].else.mother = 'jerry' #AttributeError be raised.

lxml-mate:

>>> r = ObjectifiedElementProxy( xmlstr = s )
>>> ages = [ ( p.name.pyval, p.age.pyval ) for p in r.person[:] ] #dose work
>>> r.person[0].else.mother = 'jerry' #dose work

Usage

create

to create a new xml like:

<root>
    <person height='180cm'>
        <name>jack</name>
        <age>18</age>
    </person>
</root>

lxml:

>>> from lxml import objectify, etree
>>> r = objectify.Element('root')
>>> person = objectify.SubElement( r, 'person', attrib={'height':'180cm'} )
>>> name = objectify.SubElement( person, 'name' )
>>> person.name = 'jack'
>>> age = objectify.SubElement( person, 'age' )
>>> person.age = 18

or use E-factory

>>> E = objectify.E
>>> E.root( E.person( E.name('jack'), E.age(18), height='180cm' ) )

lxml-mate:

>>> from lxmlmate import ObjectifiedElementProxy
>>> rm = ObjectifiedElementProxy( rootag='root' )
>>> rm.append( E.person( E.name('jack'), E.age(18), height='180cm' ) )

or

>>> rm = ObjectifiedElementProxy( objectifiedElement = E.root( E.person( E.name('jack'), E.age(18), height='180cm', height='180cm' ) ) )

or

>>> rm = ObjectifiedElementProxy( rootag='root' )
>>> rm.person.name = 'jack'
>>> rm.person.age = 18
>>> rm.person.attrib[ 'height' ] = '180cm'

append

to append xml snippet like:

>>>
<person>
    <name>peter</name>
    <age>45</age>
</person>
<person>
    <name>joe</name>
    <age>25</age>
</person>

lxml:

>>> r.append( E.person( E.name( 'peter' ), E.age( 45 ) ),
...           E.person( E.name( 'joe' ), E.age( 25 ) )
...          )
>>>

lxml-mate:

>>> rm.append( E.person( E.name( 'peter' ), E.age( 45 ) ),
...            E.person( E.name( 'joe' ), E.age( 25 ) )
...           )
>>>

or

>>> rm.insert( 'person', i=None )( 'name', 'peter' )( 'age', 45 )
>>> rm.insert( 'person', i=None )( 'name', 'joe' )( 'age', 25 )

select

lxml:

to select the last person ( named joe ):

>>> r.person[-1] #return an ObjectifiedElement instance.

to find persons named joe:

>>> r.xpath( '//person[name="joe"]' )  #return ObjectifiedElement instances list

lxml-mate:

>>> rm.person[-1]  #return an ObjectifiedElementProxy instance.
>>> rm.xpath( '//person[name="joe"]' )  #return ObjectifiedElementProxy objects list

remove

to remove all persons named joe:

lxml:

>>> p = r.xpath( '//person[name="joe"]' )
>>> for k in p: r.remove( k )

lxml-mate:

>>> pm = rm.xpath( '//person[name="joe"]' )
>>> rm.remove( pm )

or

>>> rm.remove( [ p for p in rm.person[:] if p.name.pyval == 'joe' ] )

to remove the first person:

lxml:

>>> p = r.person[0]
>>> r.remove( p )

lxml-mate:

>>> rm.remove( 0 )

dump to file

lxml:

>>> f = open( 'person.xml', 'w' )
>>> s = etree.tostring( r )
>>> f.write( s )
>>> f.close()

lxml-mate:

>>> rm.dump( 'person.xml' )

load from file

lxml:

>>> r = objectify.XML( 'person.xml' )

lxml-mate:

>>> rm = ObjectifiedElementProxy( xmlFile = 'person.xml' )

create a brand new xml

lxml:

>>> r = objectify.Element('root')

lxml-mate:

>>> rm = ObjectifiedElementProxy( rootag='root' )

Else

to access a tag:

>>> rm.person[0]
>>> rm[ 'person' ][0]
>>> rm.person
>>> rm.person[ 'name' ]

to modify a tag’s value:

>>> rm.person.age = 23

to get a tag’s pyval:

>>> rm.person.age.pyval

to modify a tag’s attrib:

>>> rm.person[0].attrib['height'] = "170cm"

to modify tag:

>>> rm.person[-1].tag = 'people'

to clean empty node ( no attributes & no children ):

>>> rm.clean()

You can use lxml.objectify.ObjectifiedElement’s methods directly like this:

>>> rm.addattr( 'kkk','vvv' )

Dependencies

lxml https://github.com/lxml/lxml/

Installion

>>> pip install lxml-mate

Changelog

0.5.3 (2015-07-20)

• fix ObjectifiedElementProxy( xmlFileName=’…’ ) error.

0.5.2 (2015-07-10)

• add xpath method.

• improve document and readme.rst.

0.5.0 (2015-06-29)

• initial public release.