Maintenance: Planio will be observing a scheduled maintenance window this Sunday, November 10, 2024 from 20:00 UTC until 21:00 UTC to perform important network maintenance in our primary data center. Your Planio account will be unavailable for a few minutes during this maintenance window.
Forums » Saxon/C Help and Discussions »
Should Python for .. in with XdmValue being a sequence of XdmMaps work?
Added by Martin Honnen over 2 years ago
From the documentation and some examples (although there the XdmValue seems a sequence of nodes) I take it that with SaxonC and Python you should be able to use the Python for .. in
loop on an PyXdmValue
.
But while I can do that for a sequence of nodes with e.g.
from saxonc import *
with PySaxonProcessor(license=False) as proc:
print("Test SaxonC on Python")
print(proc.version)
xpath_processor = proc.new_xpath_processor()
result = xpath_processor.evaluate('(1 to 5) ! parse-xml("<item>item " || . || "</item>")')
if result is None and xpath_processor.exception_occurred:
print(xpath_processor.error_message)
print(isinstance(result, PyXdmValue))
print(result)
for item in result:
print(isinstance(item, PyXdmItem))
print(isinstance(item, PyXdmNode))
print(item)
the same with a sequence of maps fails:
Test SaxonC on Python
SaxonC-HE 11.2 from Saxonica
True
map{"value":1}
map{"value":2}
map{"value":3}
map{"value":4}
map{"value":5}
True
False
Traceback (most recent call last):
File "C:\Users\marti\SomePath\arrays-and-maps\returnSequenceOfXdmMapsFromXPathTest2.py", line 21, in <module>
print(item)
TypeError: __str__ returned non-string (type NoneType)
Sample:
from saxonc import *
with PySaxonProcessor(license=False) as proc:
print("Test SaxonC on Python")
print(proc.version)
xpath_processor = proc.new_xpath_processor()
result = xpath_processor.evaluate('(1 to 5) ! map { "value" : . }')
if result is None and xpath_processor.exception_occurred:
print(xpath_processor.error_message)
print(isinstance(result, PyXdmValue))
print(result)
for item in result:
print(isinstance(item, PyXdmItem))
print(isinstance(item, PyXdmMap))
print(item)
Replies (4)
Please register to reply
RE: Should Python for .. in with XdmValue being a sequence of XdmMaps work? - Added by Martin Honnen over 2 years ago
Even when not trying to return the sequence of maps from XPath or XQuery but just constructing everything in Python the for .. in
fails:
from saxonc import *
with PySaxonProcessor(license=False) as proc:
print("Test SaxonC on Python")
print(proc.version)
xdm_value = PyXdmValue()
for i in range(1, 6):
xdm_value.add_xdm_item(proc.make_map2({ 'value' : proc.make_integer_value(i)}))
print(isinstance(xdm_value, PyXdmValue))
print(xdm_value)
for item in xdm_value:
print(isinstance(item, PyXdmItem))
print(isinstance(item, PyXdmMap))
print(item)
Output
Test SaxonC on Python
SaxonC-HE 11.2 from Saxonica
True
map{"value":1}
map{"value":2}
map{"value":3}
map{"value":4}
map{"value":5}
True
False
Traceback (most recent call last):
File "C:\SomePath\arrays-and-maps\createSequenceOfMapsTest1.py", line 18, in <module>
print(item)
TypeError: __str__ returned non-string (type NoneType)
It seems that should work, or shouldn't it?
RE: Should Python for .. in with XdmValue being a sequence of XdmMaps work? - Added by O'Neil Delpratt over 2 years ago
The PyXdmValue
is an iterator object which has implemented the method __iter__
. We need to do the same for the PyXdmMap
and PyXdmArray
.
RE: Should Python for .. in with XdmValue being a sequence of XdmMaps work? - Added by O'Neil Delpratt over 2 years ago
I have created the following bug issue #5342 to keep track.
RE: Should Python for .. in with XdmValue being a sequence of XdmMaps work? - Added by O'Neil Delpratt over 2 years ago
Looking back over this issue. The problem is the item_at()
method on the XmdValue does not currently support PyXdmMap
and PyXdmArray
Please register to reply