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我正在尝试修改使用 lxml.objectify 的 PyKML。使用跟踪节点追加，这将变成具有默认str()行为的字符串。我想捕获列表或元组的附加并将它们转换为适当的位置分隔行而不是 '(xx.xxxx, yy.yyyy)'

from pykml.factory import GX_ElementMaker as GX

track = GX.Track(id='track_%d' % group_num )
for pt in group:
    when = datetime.datetime.utcfromtimestamp(pt['ts'])
    track.append( KML.when( when ) )  # WHEN?
for pt in group:
    track.append( GX.coord( (pt['x'],pt['y'])) )  # <-- trouble here

谢谢，-库尔特

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1 回答 1

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使用命名空间信息创建一个干净的 ElementMaker 类。然后创建一个以节点名作为方法的子类。在这种方法中，处理所有奇怪的情况。然后制作将进入该节点名称位置的字符串，并返回具有该节点名称的干净 ElementMaker 类的实例。

http://code.google.com/r/schwehr-pykml/source/browse/src/pykml/factory.py?spec=svn05a10cef3fd3c430389e8aca1313a20da932e565&r=05a10cef3fd3c430389e8aca1313a20da932e565

def indexable_levels(args):
    #print 'args:',args
    levels = 0
    while True:
        if isinstance(args,str): break
        try:
            args = args[0]
            levels += 1
        except:
            break
    #print '   levels ->',levels
    return levels

# Create a factory object for the KML Google Extension namespace
_GX_ElementMakerSimple = objectify.ElementMaker(
    annotate=False,
    namespace=nsmap['gx'],
    nsmap={'gx': nsmap['gx']},
)

class _GX_ElementMaker (objectify.ElementMaker):
    'KML ElementMaker with overloads for custom text payloads like coordinates'
    def coord(self, *args):
        #print 'start coord: "%s"' % (str(args)), type(args), len(args)
        levels = indexable_levels(args)
        if levels == 1 and len(args) == 1:
            # This case is really redundant with the next
            assert isinstance(args[0],str)
            return _GX_ElementMakerSimple.coord(args[0])
        if levels == 1:
            return _GX_ElementMakerSimple.coord(' '.join([str(item) for item in args]))
        if levels == 2:
            # ((-121.583851, 37.386052),)
            assert(len(args)==1)
            return _GX_ElementMakerSimple.coord(' '.join([str(item) for item in args[0] ]))
        assert(False)

# Create a factory object for the KML Google Extension namespace
GX_ElementMaker = _GX_ElementMaker(
    annotate=False,
    namespace=nsmap['gx'],
    nsmap={'gx': nsmap['gx']},
)
于 2011-08-02T23:28:14.097 回答