I am making adding a character selection to a queue accept tool using radiobuttons for the characters.
the character selection is based on object detection using cv2, and I need to make it so whatever character you select affects the file cv2 opens.
This is what I'm using:
def selection():
if select:
screenshot = wincap.get_screenshot()
# Import selection to Vision Class
test=0
test=v.get()
characterSearch = charSearch('./CharacterSelect/' + str(characters[test]+'.jpg'))
print('./CharacterSelect/' + str(characters[test]+'.jpg'))
characterMatch = characterSearch.find(screenshot, .63, 'rectangles')
if len(characterMatch):
charSelect_off()
window.after(500, selection)
#Stores interger values
v = IntVar()
v.set = ()
# Radio button loops for character select
for index in range(len(characters)):
Radiobutton(bottomframe,
compound = TOP,
image = portraits[index],
text = characters[index],
variable = v,
value = index,
).grid(
row = index//5,
column = index%5,
)
This errors saying it can't find the path.
the print however is able to print selection.
So I need to find a way to create a dynamic str with cv2.imread() in order to do this. or another option entirely, like if I can read it from a list of images loaded via tkinter, that would work too as I have a list built, so if i could index that, that would also be more optimal.
Edit:
Adding the error received:
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\lugex\AppData\Local\Programs\Python\Python311\Lib\tkinter\__init__.py", line 1948, in __call__
return self.func(*args)
^^^^^^^^^^^^^^^^
File "C:\Users\lugex\AppData\Local\Programs\Python\Python311\Lib\tkinter\__init__.py", line 861, in callit
func(*args)
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\main.py", line 182, in start
win32gui.SetForegroundWindow(handle)
pywintypes.error: (0, 'SetForegroundWindow', 'No error message is available')
[ WARN:0#11.286] global D:\a\opencv-python\opencv-python\opencv\modules\imgcodecs\src\loadsave.cpp (239) cv::findDecoder imread_('./CharacterSelect/Adriana.jpg'): can't open/read file: check file path/integrity
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\lugex\AppData\Local\Programs\Python\Python311\Lib\tkinter\__init__.py", line 1948, in __call__
return self.func(*args)
^^^^^^^^^^^^^^^^
File "C:\Users\lugex\AppData\Local\Programs\Python\Python311\Lib\tkinter\__init__.py", line 861, in callit
func(*args)
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\main.py", line 188, in start
search_on()
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\main.py", line 154, in search_on
Char_Search()
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\main.py", line 207, in Char_Search
search_off()
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\main.py", line 160, in search_off
charSelect_on()
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\main.py", line 165, in charSelect_on
selection()
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\main.py", line 220, in selection
characterSearch = charSearch('./CharacterSelect/' + str(characters[test]+'.jpg'))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "c:\Users\lugex\OneDrive\Documents\Projects\Queue-Companion\vision.py", line 206, in __init__
self.accept_w = self.accept_img.shape[1]
^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'shape'
I was able to figure this out when I found this: https://stackoverflow.com/a/48562343/20593304
creating a dynamic path using the string I created.
charVariable=0
charVariable=v.get()
pathtoCharacters = os.path.join(os.getcwd(), "CharacterSearch", str(characters[charVariable]+".jpg"))
characterSearch = charSearch(pathtoCharacters)
which then implements to my class that performs the object detection.
Related
I was trying this tutorial given in the MistQL for a personal work but this below code is throwing exception as given below
import mistql
data="{\"foo\": \"bar\"}"
query = '#.foo'
results = mistql.query(query, data)
print(results)
Traceback (most recent call last): File "C:\Temp\sample.py", line 4,
in
purchaserEmails = mistql.query(query, data) File "C:\Python3.10.0\lib\site-packages\mistql\query.py", line 18, in query
result = execute_outer(ast, data) File "C:\Python3.10.0\lib\site-packages\mistql\execute.py", line 73, in
execute_outer
return execute(ast, build_initial_stack(data, builtins)) File "C:\Python3.10.0\lib\site-packages\typeguard_init_.py", line 1033,
in wrapper
retval = func(*args, **kwargs) File "C:\Python3.10.0\lib\site-packages\mistql\execute.py", line 60, in
execute
return execute_fncall(ast.fn, ast.args, stack) File "C:\Python3.10.0\lib\site-packages\typeguard_init_.py", line 1033,
in wrapper
retval = func(*args, **kwargs) File "C:\Python3.10.0\lib\site-packages\mistql\execute.py", line 28, in
execute_fncall
return function_definition(arguments, stack, execute) File "C:\Python3.10.0\lib\site-packages\mistql\builtins.py", line 37, in
wrapped
return fn(arguments, stack, exec) File "C:\Python3.10.0\lib\site-packages\mistql\builtins.py", line 168, in
dot
return _index_single(RuntimeValue.of(right.name), left) File "C:\Python3.10.0\lib\site-packages\mistql\builtins.py", line 295, in
_index_single
assert_type(index, RVT.Number) File "C:\Python3.10.0\lib\site-packages\mistql\runtime_value.py", line 344,
in assert_type
raise MistQLTypeError(f"Expected {expected_type}, got {value.type}") mistql.exceptions.MistQLTypeError: Expected
RuntimeValueType.Number, got RuntimeValueType.String
Strings passed as data into MistQL's query method correspond to MistQL string types, and thus the #.foo query is attempting to index the string "{\"foo\": \"bar\"}") using the "foo" value, leading to the error above.
MistQL is expecting native dictionaries and lists. The correspondence between Python data types and MistQL data types can be seen here
That being said, the error message is indeed very confusing and should be fixed post-haste! Issue here
I am reading a set of coordinates from a file to produce a shape in the Python Turtle. After reading reading in the coordinates, I have written a for loop that goes through the list of coords and draws them. However, upon running with a correct file name, I get this error:
Traceback (most recent call last):
File "C:\Users\06113\Desktop\My Stuff\Python Saves\Vec Draw\Vec Draw.py", line 55, in <module>
t.goto(cs)
File "C:\Users\06113\AppData\Local\Programs\Python\Python38-32\lib\turtle.py", line 1774, in goto
self._goto(Vec2D(*x))
File "C:\Users\06113\AppData\Local\Programs\Python\Python38-32\lib\turtle.py", line 3195, in _goto
self._update() #count=True)
File "C:\Users\06113\AppData\Local\Programs\Python\Python38-32\lib\turtle.py", line 2660, in _update
self._update_data()
File "C:\Users\06113\AppData\Local\Programs\Python\Python38-32\lib\turtle.py", line 2650, in _update_data
self.screen._drawline(self.currentLineItem, self.currentLine,
File "C:\Users\06113\AppData\Local\Programs\Python\Python38-32\lib\turtle.py", line 543, in _drawline
cl.append(x * self.xscale)
TypeError: can't multiply sequence by non-int of type 'float'
Is there any way at all that I could fix this in MY file? I would rather not go into the turtle module where I could easily mess something up.
The code for this section in my file is:
t = turtle.Turtle(visible=False)
t.speed(0)
for i in range(0, len(coord_list), 2):
if i == 0 and i+1 == 1:
fcs = (coord_list[i], coord_list[i+1])
t.pu()
t.goto(fcs)
t.pd()
pass
else:
cs = (coord_list[i], coord_list[i+1])
t.goto(cs)
cs = None
pass
pass
t.goto(fcs)
print("Vector image drawn.")
I've a dictionary consisting of keys = word, value = Array of 300 float numbers.
I'm unable to use this dictionary in my pyspark UDF.
When size of this dictionary is 2Million keys it does not work. But when I reduce the size to 200K it works.
This is my code for the function to be converted to UDF
def get_sentence_vector(sentence, dictionary_containing_word_vectors):
cleanedSentence = list(clean_text(sentence))
words_vector_list = np.zeros(300)# 300 dimensional vector
for x in cleanedSentence:
try:
words_vector_list = np.add(words_vector_list, dictionary_containing_word_vectors[str(x)])
except Exception as e:
print("Exception caught while finding word vector from Fast text pretrained model Dictionary: ",e)
return words_vector_list.tolist()
This is my UDF
get_sentence_vector_udf = F.udf(lambda val: get_sentence_vector(val, fast_text_dictionary), ArrayType(FloatType()))
This is how i'm calling the udf to be added as a column in my dataframe
dmp_df_with_vectors = df.filter(df.item_name.isNotNull()).withColumn("sentence_vector", get_sentence_vector_udf(df.item_name))
And this is the stack trace for the error
Traceback (most recent call last):
File "/usr/lib/spark/python/pyspark/broadcast.py", line 83, in dump
pickle.dump(value, f, 2)
SystemError: error return without exception set
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/spark/python/pyspark/sql/functions.py", line 1957, in wrapper
return udf_obj(*args)
File "/usr/lib/spark/python/pyspark/sql/functions.py", line 1916, in __call__
judf = self._judf
File "/usr/lib/spark/python/pyspark/sql/functions.py", line 1900, in _judf
self._judf_placeholder = self._create_judf()
File "/usr/lib/spark/python/pyspark/sql/functions.py", line 1909, in _create_judf
wrapped_func = _wrap_function(sc, self.func, self.returnType)
File "/usr/lib/spark/python/pyspark/sql/functions.py", line 1866, in _wrap_function
pickled_command, broadcast_vars, env, includes = _prepare_for_python_RDD(sc, command)
File "/usr/lib/spark/python/pyspark/rdd.py", line 2377, in _prepare_for_python_RDD
broadcast = sc.broadcast(pickled_command)
File "/usr/lib/spark/python/pyspark/context.py", line 799, in broadcast
return Broadcast(self, value, self._pickled_broadcast_vars)
File "/usr/lib/spark/python/pyspark/broadcast.py", line 74, in __init__
self._path = self.dump(value, f)
File "/usr/lib/spark/python/pyspark/broadcast.py", line 90, in dump
raise pickle.PicklingError(msg)
cPickle.PicklingError: Could not serialize broadcast: SystemError: error return without exception set
How big is your fast_text_dictionary in the 2M case? It might be too big.
Try broadcast it first before running udf. e.g.
broadcastVar = sc.broadcast(fast_text_dictionary)
Then use broadcastVar instead in your udf.
See the document for broadcast
I'm a beginner with myhdl.
I try to translate the following Verilog code to MyHDL:
module ModuleA(data_in, data_out, clk);
input data_in;
output reg data_out;
input clk;
always #(posedge clk) begin
data_out <= data_in;
end
endmodule
module ModuleB(data_in, data_out, clk);
input [1:0] data_in;
output [1:0] data_out;
input clk;
ModuleA instance1(data_in[0], data_out[0], clk);
ModuleA instance2(data_in[1], data_out[1], clk);
endmodule
Currently, I have this code:
import myhdl
#myhdl.block
def ModuleA(data_in, data_out, clk):
#myhdl.always(clk.posedge)
def logic():
data_out.next = data_in
return myhdl.instances()
#myhdl.block
def ModuleB(data_in, data_out, clk):
instance1 = ModuleA(data_in(0), data_out(0), clk)
instance2 = ModuleA(data_in(1), data_out(1), clk)
return myhdl.instances()
# Create signals
data_in = myhdl.Signal(myhdl.intbv()[2:])
data_out = myhdl.Signal(myhdl.intbv()[2:])
clk = myhdl.Signal(bool())
# Instantiate the DUT
dut = ModuleB(data_in, data_out, clk)
# Convert tfe DUT to Verilog
dut.convert()
But it doesn't works because signal slicing produce a read-only shadow signal (cf MEP-105).
So, what is it the good way in MyHDL to have a writable slice of a signal?
Edit:
This is the error I get
$ python demo.py
Traceback (most recent call last):
File "demo.py", line 29, in <module>
dut.convert()
File "/home/killruana/.local/share/virtualenvs/myhdl_sandbox-dYpBu4o5/lib/python3.6/site-packages/myhdl-0.10-py3.6.egg/myhdl/_block.py", line 342, in convert
File "/home/killruana/.local/share/virtualenvs/myhdl_sandbox-dYpBu4o5/lib/python3.6/site-packages/myhdl-0.10-py3.6.egg/myhdl/conversion/_toVerilog.py", line 177, in __call__
File "/home/killruana/.local/share/virtualenvs/myhdl_sandbox-dYpBu4o5/lib/python3.6/site-packages/myhdl-0.10-py3.6.egg/myhdl/conversion/_analyze.py", line 170, in _analyzeGens
File "/usr/lib/python3.6/ast.py", line 253, in visit
return visitor(node)
File "/home/killruana/.local/share/virtualenvs/myhdl_sandbox-dYpBu4o5/lib/python3.6/site-packages/myhdl-0.10-py3.6.egg/myhdl/conversion/_analyze.py", line 1072, in visit_Module
File "/home/killruana/.local/share/virtualenvs/myhdl_sandbox-dYpBu4o5/lib/python3.6/site-packages/myhdl-0.10-py3.6.egg/myhdl/conversion/_misc.py", line 148, in raiseError
myhdl.ConversionError: in file demo.py, line 4:
Signal has multiple drivers: data_out
You can use an intermediate list of Signal(bool()) as placeholder.
#myhdl.block
def ModuleB(data_in, data_out, clk):
tsig = [myhdl.Signal(bool(0)) for _ in range(len(data_in))]
instances = []
for i in range(len(data_in)):
instances.append(ModuleA(data_in(i), tsig[i], clk))
#myhdl.always_comb
def assign():
for i in range(len(data_out)):
data_out.next[i] = tsig[i]
return myhdl.instances()
A quick (probably non-fulfilling) comment, is that the intbv is treated as a single entity that can't have multiple drives. Two references that might help shed some light:
http://jandecaluwe.com/hdldesign/counting.html
http://docs.myhdl.org/en/stable/manual/structure.html#converting-between-lists-of-signals-and-bit-vectors
I've just started using pycassa, so if this is a stupid question, I apologize upfront.
I have a column family with the following schema:
create column family MyColumnFamilyTest
with column_type = 'Standard'
and comparator = 'CompositeType(org.apache.cassandra.db.marshal.UTF8Type,org.apache.cassandra.db.marshal.UTF8Type,org.apache.cassandra.db.marshal.UTF8Type,org.apache.cassandra.db.marshal.TimeUUIDType)'
and default_validation_class = 'BytesType'
and key_validation_class = 'UTF8Type'
and read_repair_chance = 0.1
and dclocal_read_repair_chance = 0.0
and populate_io_cache_on_flush = false
and gc_grace = 864000
and min_compaction_threshold = 4
and max_compaction_threshold = 32
and replicate_on_write = true
and compaction_strategy = 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'
and caching = 'KEYS_ONLY'
and compression_options = {'sstable_compression' : 'org.apache.cassandra.io.compress.SnappyCompressor'};
When I try to do a get() with a valid key (works fine in cassandra-cli) I get:
Traceback (most recent call last):
File "<pyshell#19>", line 1, in <module>
cf.get('mykey',column_count=3)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 664, in get
return self._cosc_to_dict(list_col_or_super, include_timestamp, include_ttl)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 368, in _cosc_to_dict
ret[self._unpack_name(col.name)] = self._col_to_dict(col, include_timestamp, include_ttl)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 444, in _unpack_name
return self._name_unpacker(b)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/marshal.py", line 140, in unpack_composite
components.append(unpacker(bytestr[2:2 + length]))
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/marshal.py", line 374, in <lambda>
return lambda v: uuid.UUID(bytes=v)
File "/usr/lib/python2.7/uuid.py", line 144, in __init__
raise ValueError('bytes is not a 16-char string')
ValueError: bytes is not a 16-char string
Here's some more information I've discovered:
When using cassandra-cli I can see the data as:
% cassandra-cli -h 10.249.238.131
Connected to: "LocalDB" on 10.249.238.131/9160
Welcome to Cassandra CLI version 1.2.10-SNAPSHOT
Type 'help;' or '?' for help.
Type 'quit;' or 'exit;' to quit.
[default#unknown] use Keyspace;
[default#Keyspace] list ColumnFamily;
Using default limit of 100
Using default cell limit of 100
-------------------
RowKey: urn:keyspace:ColumnFamily:a36e8ab1-7032-4e4c-a53d-e3317f63a640:
=> (name=autoZoning:::, value=01, timestamp=1391298393966000)
=> (name=creationTime:::, value=00000143efd8b76e, timestamp=1391298393966000)
=> (name=inactive:::14fe78e0-8b9b-11e3-b171-005056b700bb, value=00, timestamp=1391298393966000)
=> (name=label:::14fe78e0-8b9b-11e3-b171-005056b700bb, value=726a6d2d766e782d76613031, timestamp=1391298393966000)
1 Row Returned.
Elapsed time: 16 msec(s).
Since it was unclear what was causing the exception, I decided to add a print prior to the 'return self._name_unpacker(b)' line in columnfamily.py and I see:
>>> cf.get(dict(cf.get_range(column_count=0,filter_empty=False)).keys()[0])
Attempting to unpack: <00>\rautoZoning<00><00><00><00><00><00><00><00><00><00>
Traceback (most recent call last):
File "<pyshell#172>", line 1, in <module>
cf.get(dict(cf.get_range(column_count=0,filter_empty=False)).keys()[0])
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 665, in get
return self._cosc_to_dict(list_col_or_super, include_timestamp, include_ttl)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 368, in _cosc_to_dict
ret[self._unpack_name(col.name)] = self._col_to_dict(col, include_timestamp, include_ttl)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 445, in _unpack_name
return self._name_unpacker(b)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/marshal.py", line 140, in unpack_composite
components.append(unpacker(bytestr[2:2 + length]))
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/marshal.py", line 374, in <lambda>
return lambda v: uuid.UUID(bytes=v)
File "/usr/lib/python2.7/uuid.py", line 144, in __init__
raise ValueError('bytes is not a 16-char string')
ValueError: bytes is not a 16-char string
I have no idea where the extra characters are coming from around the column name. But that got me curious so I added another print in _cosc_to_dict in columnfamily.py and I see:
>>> cf.get(dict(cf.get_range(column_count=0,filter_empty=False)).keys()[0])
list_col_or_super is: []
list_col_or_super is: [ColumnOrSuperColumn(column=Column(timestamp=1391298393966000,
name='\x00\rautoZoning\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00', value='\x01', ttl=None),
counter_super_column=None, super_column=None, counter_column=None),
ColumnOrSuperColumn(column=Column(timestamp=1391298393966000,
name='\x00\x0ccreationTime\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
value='\x00\x00\x01C\xef\xd8\xb7n', ttl=None), counter_super_column=None, super_column=None,
counter_column=None), ColumnOrSuperColumn(column=Column(timestamp=1391298393966000,
name='\x00\x08inactive\x00\x00\x00\x00\x00\x00\x00\x00\x10\x14\xfex\xe0\x8b\x9b\x11\xe3\xb1q\x00PV\xb7\x00\xbb\x00', value='\x00', ttl=None), counter_super_column=None, super_column=None,
counter_column=None), ColumnOrSuperColumn(column=Column(timestamp=1391298393966000,
name='\x00\x05label\x00\x00\x00\x00\x00\x00\x00\x00\x10\x14\xfex\xe0\x8b\x9b\x11\xe3\xb1q\x00PV\xb7\x00\xbb\x00', value='thisIsATest', ttl=None), counter_super_column=None, super_column=None, counter_column=None)]
autoZoning unpack:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib64/python2.6/site-packages/pycassa-1.11.0-py2.6.egg/pycassa/columnfamily.py", line 666, in get
return self._cosc_to_dict(list_col_or_super, include_timestamp, include_ttl)
File "/usr/local/lib64/python2.6/site-packages/pycassa-1.11.0-py2.6.egg/pycassa/columnfamily.py", line 369, in _cosc_to_dict
ret[self._unpack_name(col.name)] = self._col_to_dict(col, include_timestamp, include_ttl)
File "/usr/local/lib64/python2.6/site-packages/pycassa-1.11.0-py2.6.egg/pycassa/columnfamily.py", line 446, in _unpack_name
return self._name_unpacker(b)
File "/usr/local/lib64/python2.6/site-packages/pycassa-1.11.0-py2.6.egg/pycassa/marshal.py", line 140, in unpack_composite
components.append(unpacker(bytestr[2:2 + length]))
File "/usr/local/lib64/python2.6/site-packages/pycassa-1.11.0-py2.6.egg/pycassa/marshal.py", line 374, in <lambda>
return lambda v: uuid.UUID(bytes=v)
File "/usr/lib64/python2.6/uuid.py", line 144, in __init__
raise ValueError('bytes is not a 16-char string')
ValueError: bytes is not a 16-char string
Am I correct in assuming that the extra characters around the column names are what is responsible for the 'ValueError: bytes is not a 16-char string' exception?
Also if I try to use the column name and select it I get:
>>> cf.get(u'urn:keyspace:ColumnFamily:a36e8ab1-7032-4e4c-a53d-e3317f63a640:',columns=['autoZoning:::'])
Traceback (most recent call last):
File "<pyshell#184>", line 1, in <module>
cf.get(u'urn:keyspace:ColumnFamily:a36e8ab1-7032-4e4c-a53d-e3317f63a640:',columns=['autoZoning:::'])
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 651, in get
cp = self._column_path(super_column, column)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 383, in _column_path
self._pack_name(column, False))
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/columnfamily.py", line 426, in _pack_name
return self._name_packer(value, slice_start)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/marshal.py", line 115, in pack_composite
packed = packer(item)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/marshal.py", line 298, in pack_uuid
randomize=True)
File "/usr/local/lib/python2.7/dist-packages/pycassa-1.11.0-py2.7.egg/pycassa/util.py", line 75, in convert_time_to_uuid
'neither a UUID, a datetime, or a number')
ValueError: Argument for a v1 UUID column name or value was neither a UUID, a datetime, or a number
Any further thoughts?
Thanks,
Rob
Turns out that the problem wasn't with the key, it was being caused, in part, by a bug in pycassa that wasn't handling an empty (null) string in the column UUID. A short-term fix is in the answer in google groups:
https://groups.google.com/d/msg/pycassa-discuss/Vf_bSgDIi9M/KTA1kbE9IXAJ
The other part of the answer was to get at the columns by using tuples (with the UUID as a UUID and not a str) instead of a string with ':' separators because that's, as I found out, a cassandra-cli thing.