I have the following function and the following call (with the connection setup before it)
from neo4j import GraphDatabase
from pypher import Pypher
# from WebScraper import *
py = Pypher()
# server connection link
uri = "bolt://localhost:7687"
driver = GraphDatabase.driver(uri, auth=("neo4j", "cs411fpl"))
session = driver.session()
username = 'a'
varray = []
# adds a user node
def add_user(username_):
q1 = "CREATE (u:User) SET u.name= $username_"
nodes = session.run(q1)
add_user(username)
This leads to the error:
File "UserHandler.py", line 37, in <module>
add_user(username)
File "UserHandler.py", line 14, in add_user
nodes = session.run(q1)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/neo4j/work/simple.py", line 217, in run
self._autoResult._run(query, parameters, self._config.database, self._config.default_access_mode, self._bookmarks, **kwparameters)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/neo4j/work/result.py", line 101, in _run
self._attach()
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/neo4j/work/result.py", line 202, in _attach
self._connection.fetch_message()
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/neo4j/io/_bolt4.py", line 363, in fetch_message
response.on_failure(summary_metadata or {})
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/neo4j/io/_common.py", line 179, in on_failure
raise Neo4jError.hydrate(**metadata)
neo4j.exceptions.ClientError: {code: Neo.ClientError.Statement.ParameterMissing} {message: Expected parameter(s): username_}
Any suggestions would be great. Thanks!
You are missing the connectiong between Cypher and Python (a second argument to run). It is not enough to have spelled username_ the same way both places.
def add_user(username_):
q1 = "CREATE (u:User) SET u.name= $username_"
nodes = session.run(q1, username_=username_)
I think the following would work as well, notice how the second argument for run must describe the coupling between the Cypher and Python:
def add_user(username_):
q1 = "CREATE (u:User) SET u.name= $login"
nodes = session.run(q1, login=username_)
You might be able to find more here:
https://neo4j.com/developer/python/
from pyalgotrade import strategy
from pyalgotrade.feed import csvfeed
from pyalgotrade.technical import ma
from pyalgotrade.bar import Frequency
class MyStrategy(strategy.BacktestingStrategy):
def __init__(self, feed, instrument):
strategy.BacktestingStrategy.__init__(self, feed, 1000)
# We want a 15 period SMA over the closing prices.
self.__instrument = instrument
self.__sma = ma.SMA(feed[instrument].getDataSeries(instrument), 15)
def onBars(self, bars):
bar = bars[self.__instrument]
print "%s: %s %s" % (bar.getDateTime(), self.__sma[-1])
# Load the yahoo feed from the CSV file
feed = csvfeed.Feed("Date","%Y-%m-%d %H:%M")
feed.addValuesFromCSV("test.csv")
# Evaluate the strategy with the feed's bars.
rules = MyStrategy(feed, "Open")
rules.run()
I'm getting following error:
Traceback (most recent call last):
File "algotrade.py", line 21, in <module>
rules = MyStrategy(feed, "Open")
File "algotrade.py", line 11, in __init__
self.__sma = ma.SMA(feed[instrument].getDataSeries(instrument), 15)
AttributeError: 'SequenceDataSeries' object has no attribute 'getDataSeries'
I cant figure out the problem of my code and the tutorial on pyalgotrade is not helpful for me.
The problem is that you're using a regular Feed class instead of a BarFeed. Try using this: https://github.com/gbeced/pyalgotrade/blob/master/pyalgotrade/barfeed/csvfeed.py#L190
I am using rpy2 to run some R commands. Dont ask why. It's necessary at this moment. So here's a part of the code.
import pandas.rpy.common as com
from rpy2.robjects import r
#Load emotionsCART decision tree. Successful.
r_dataframe = com.convert_to_r_dataframe(data)
print type(r_dataframe)
(<class 'rpy2.robjects.vectors.DataFrame'>)
r('pred = predict(emotionsCART, newdata = %s)') %(r_dataframe)
Here what I want to do is pass this r_dataframe into the calculation. I'm using the decision tree that I'd loaded earlier to predict the values. But the last line gives me an error. It says
Traceback (most recent call last):
File "<pyshell#38>", line 1, in <module>
r('pred = predict(emotionsCART, newdata = %s)') %(r_dataframe)
File "C:\Python27\lib\site-packages\rpy2\robjects\__init__.py", line 245, in __call__
p = rinterface.parse(string)
ValueError: Error while parsing the string.
Ideas why this is happening?
I think that:
r('pred = predict(emotionsCART, newdata = %s)') %(r_dataframe)
SHould be:
r('pred = predict(emotionsCART, newdata = %s)' % (r_dataframe) )
The %(r_dataframe) was associated with the r() part, while it should be associated with the '' (string).
But it is hard to check without a reproducible example.
We are using the cocos2d framework to create a game. We're completely new to this framework, so we cannot get the director object to work as we are expecting. Here is our code skeleton:
from cocos.director import director
from cocos.layer import base_layers
import sys
import math
import os
import pyglet
import cocos
world_width = 1000
world_height = 1000
class NetworkMap(cocos.layer.ScrollableLayer):
def __init__(self, world_width, world_height):
self.world_width = world_width
self.world_height = world_height
super(NetworkMap, self).__init__()
bg = ColorLayer(170,170,0,255,width=500,height=500)
self.px_width = world_width
self.px_height = world_height
self.add(bg,z=0)
class TestScene(cocos.scene.Scene):
def __init__(self):
super(TestScene,self).__init__()
def on_enter():
director.push_handlers(self.on_cocos_resize)
super(TestScene, self).on_enter()
def on_cocos_resize(self, usable_width, usable_height):
self.f_refresh_marks()
def main():
scene = TestScene()
director.init(world_width, world_height, do_not_scale=True)
world_map = NetworkMap(world_width, world_height)
scroller = cocos.layer.ScrollingManager()
scroller.add(world_map)
scene.add(scroller)
director.run(scene)
So for some reason the director doesn't have all the attributes we want.
Our stack trace is:
Traceback (most recent call last):
File "map.py", line 49, in <module>
main()
File "map.py", line 39, in main
scene = TestScene()
File "map.py", line 29, in __init__
super(TestScene,self).__init__()
File "/usr/local/lib/python2.7/dist-packages/cocos2d-0.5.5-py2.7.egg/cocos/scene.py", line 95, in __init__
super(Scene,self).__init__()
File "/usr/local/lib/python2.7/dist-packages/cocos2d-0.5.5-py2.7.egg/cocos/cocosnode.py", line 114, in __init__
self.camera = Camera()
File "/usr/local/lib/python2.7/dist-packages/cocos2d-0.5.5-py2.7.egg/cocos/camera.py", line 56, in __init__
self.restore()
File "/usr/local/lib/python2.7/dist-packages/cocos2d-0.5.5-py2.7.egg/cocos/camera.py", line 76, in restore
width, height = director.get_window_size()
File "/usr/local/lib/python2.7/dist-packages/cocos2d-0.5.5-py2.7.egg/cocos/director.py", line 522, in get_window_size
return ( self._window_virtual_width, self._window_virtual_height)
AttributeError: 'Director' object has no attribute '_window_virtual_width'
You need to initialise the director before you instantiate your first scene. The director is the global object that initialises your screen, sets up the Cocos2D framework, etc.
I found a few other errors:
You need to change ColorLayer to be fully qualified, e.g. cocos.layer.ColorLayer.
on_enter needs to have self as the first argument.
You need to define f_refresh_marks in your TestScene class.
Here's a working copy of the code. (Working, in the sense that it does not throw errors, not that it does any sort of scrolling.)
from cocos.director import director
from cocos.layer import base_layers
import sys
import math
import os
import pyglet
import cocos
world_width = 1000
world_height = 1000
class NetworkMap(cocos.layer.ScrollableLayer):
def __init__(self, world_width, world_height):
self.world_width = world_width
self.world_height = world_height
super(NetworkMap, self).__init__()
bg = cocos.layer.ColorLayer(170,170,0,255,width=500,height=500)
self.px_width = world_width
self.px_height = world_height
self.add(bg,z=0)
class TestScene(cocos.scene.Scene):
def __init__(self):
super(TestScene,self).__init__()
def on_enter(self):
director.push_handlers(self.on_cocos_resize)
super(TestScene, self).on_enter()
def on_cocos_resize(self, usable_width, usable_height):
self.f_refresh_marks()
def f_refresh_marks(self):
pass
def main():
director.init(world_width, world_height, do_not_scale=True)
scene = TestScene()
world_map = NetworkMap(world_width, world_height)
scroller = cocos.layer.ScrollingManager()
scroller.add(world_map)
scene.add(scroller)
director.run(scene)
if __name__ == '__main__': main()
I had the same issue (with a very similar stack trace) and it was because I was trying to create a layer before calling director.init(). Moving director.init() to earlier in the code fixed it for me.
I have three pieces of code that i'm working with at the moment:
A closed source application (Main.exe)
A closed source VB COM object implemented as a dll (comobj.dll)
Code that I am developing in Python
comobj.dll hosts a COM object (lets say, 'MainInteract') that I would like to use from Python. I can already use this object perfectly fine from IronPython, but due to other requirements I need to use it from regular Python. I believe the best method here is to use win32com, but I can't quite make any headway at all.
First, some working IronPython code:
import clr
import os
import sys
__dir__ = os.path.dirname(os.path.realpath(__file__))
sys.path.insert(0, __dir__)
sys.path.append(r"C:\Path\To\comobj.dll") #This is where the com object dll actually is
clr.AddReferenceToFileAndPath(os.path.join(__dir__, r'comobj_1_1.dll')) #This is the .NET interop assembly that was created automatically via SharpDevelop's COM Inspector
from comobj_1_1 import clsMainInteract
o = clsMainInteract()
o.DoStuff(True)
And now the code that I attempted in regular Python:
>>> import win32com.client
>>> win32com.client.Dispatch("{11111111-comobj_guid_i_got_from_com_inspector}")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python26\lib\site-packages\win32com\client\__init__.py", line 95, in Dispatch
dispatch, userName = dynamic._GetGoodDispatchAndUserName(dispatch,userName,clsctx)
File "C:\Python26\lib\site-packages\win32com\client\dynamic.py", line 104, in _GetGoodDispatchAndUserName
return (_GetGoodDispatch(IDispatch, clsctx), userName)
File "C:\Python26\lib\site-packages\win32com\client\dynamic.py", line 84, in _GetGoodDispatch
IDispatch = pythoncom.CoCreateInstance(IDispatch, None, clsctx, pythoncom.IID_IDispatch)
pywintypes.com_error: (-2147221164, 'Class not registered', None, None)
I have also attempted using the friendly name of the TLB:
>>> import win32com.client
>>> win32com.client.Dispatch("Friendly TLB Name I Saw")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python26\lib\site-packages\win32com\client\__init__.py", line 95, in Dispatch
dispatch, userName = dynamic._GetGoodDispatchAndUserName(dispatch,userName,clsctx)
File "C:\Python26\lib\site-packages\win32com\client\dynamic.py", line 104, in _GetGoodDispatchAndUserName
return (_GetGoodDispatch(IDispatch, clsctx), userName)
File "C:\Python26\lib\site-packages\win32com\client\dynamic.py", line 84, in _GetGoodDispatch
IDispatch = pythoncom.CoCreateInstance(IDispatch, None, clsctx, pythoncom.IID_IDispatch)
pywintypes.com_error: (-2147221005, 'Invalid class string', None, None)
In fact, the only success I've had was this:
import pythoncom
tlb = pythoncom.LoadRegTypeLib("{11111111-comobj_guid_i_got_from_com_inspector}",1,1,0)
>>> tlb
<PyITypeLib at 0x00AD7D78 with obj at 0x0025EDF0>
>>> tlb.GetDocumentation(1)
(u'clsMainInteract', None, 0, None)
But i'm not sure how to go from there to getting an object. I think my problem is that I need to load the dll into my process and get it to register itself with my process's COM source, so I can properly CoCreateInstance / win32com.client.Dispatch() on it.
I have also seen Activation Contexts referenced, especially when talking about 'no registration COM', but typically in a sentences like "Windows will create a context for you if you specify the right stuff in your .manifest files". I'd like to avoid manifest files if possible, as one would be required in the same folder as the (closed source) COM object dll, and i'd rather not drop any files in that directory if I can avoid it.
Thanks for the help.
What I did to access Free Download Manager's type library was the following:
import pythoncom, win32com.client
fdm = pythoncom.LoadTypeLib('fdm.tlb')
downloads_stat = None
for index in xrange(0, fdm.GetTypeInfoCount()):
type_name = fdm.GetDocumentation(index)[0]
if type_name == 'FDMDownloadsStat':
type_iid = fdm.GetTypeInfo(index).GetTypeAttr().iid
downloads_stat = win32com.client.Dispatch(type_iid)
break
downloads_stat.BuildListOfDownloads(True, True)
print downloads_stat.Download(0).Url
The code above will print the URL of the first download.
Here is a method I devised to load a COM object from a DLL. It was based on a lot of reading about COM, etc. I'm not 100% sure about the last lines, specifically d=. I think that only works if IID_Dispatch is passed in (which you can see if the default param).
In addition, I believe this code leaks - for one, the DLL is never unloaded (use ctypes.windll.kernel32.FreeLibraryW) and I believe the COM ref counts for the initial class factory are off by one, and thus never get released. But still, this works for my application.
import pythoncom
import win32com.client
def CreateInstanceFromDll(dll, clsid_class, iid_interface=pythoncom.IID_IDispatch, pUnkOuter=None, dwClsContext=pythoncom.CLSCTX_SERVER):
from uuid import UUID
from ctypes import OleDLL, c_long, byref
e = OleDLL(dll)
clsid_class = UUID(clsid_class).bytes_le
iclassfactory = UUID(str(pythoncom.IID_IClassFactory)).bytes_le
com_classfactory = c_long(0)
hr = e.DllGetClassObject(clsid_class, iclassfactory, byref(com_classfactory))
MyFactory = pythoncom.ObjectFromAddress(com_classfactory.value, pythoncom.IID_IClassFactory)
i = MyFactory.CreateInstance(pUnkOuter, iid_interface)
d = win32com.client.__WrapDispatch(i)
return d
For a useful utility module that wraps the object-from-DLL case, as well as others, see https://gist.github.com/4219140
__all__ = (
####### Class Objects
#CoGetClassObject - Normal, not wrapped
'CoDllGetClassObject', #Get ClassObject from a DLL file
####### ClassFactory::CreateInstance Wrappers
'CoCreateInstanceFromFactory', #Create an object via IClassFactory::CreateInstance
'CoCreateInstanceFromFactoryLicenced', #Create a licenced object via IClassFactory2::CreateInstanceLic
###### Util
'CoReleaseObject', #Calls Release() on a COM object
###### Main Utility Methods
#'CoCreateInstance', #Not wrapped, normal call
'CoCreateInstanceLicenced', #CoCreateInstance, but with a licence key
###### Hacky DLL methods for reg-free COM without Activation Contexts, manifests, etc
'CoCreateInstanceFromDll', #Given a dll, a clsid, and an iid, create an object
'CoCreateInstanceFromDllLicenced', #Given a dll, a clsid, an iid, and a license key, create an object
)
IID_IClassFactory2 = "{B196B28F-BAB4-101A-B69C-00AA00341D07}"
from uuid import UUID
from ctypes import OleDLL, WinDLL, c_ulong, byref, WINFUNCTYPE, POINTER, c_char_p, c_void_p
from ctypes.wintypes import HRESULT
import pythoncom
import win32com.client
import logging
log = logging.getLogger(__name__)
def _raw_guid(guid):
"""Given a string GUID, or a pythoncom IID, return the GUID laid out in memory suitable for passing to ctypes"""
return UUID(str(guid)).bytes_le
proto_icf2_base = WINFUNCTYPE(HRESULT,
c_ulong,
c_ulong,
c_char_p,
c_ulong,
POINTER(c_ulong),
)
IClassFactory2__CreateInstanceLic = proto_icf2_base(7, 'CreateInstanceLic', (
(1, 'pUnkOuter'),
(1 | 4, 'pUnkReserved'),
(1, 'riid'),
(1, 'bstrKey'),
(2, 'ppvObj'),
), _raw_guid(IID_IClassFactory2))
#--------------------------------
#--------------------------------
def _pc_wrap(iptr, resultCLSID=None):
#return win32com.client.__WrapDispatch(iptr)
log.debug("_pc_wrap: %s, %s"%(iptr, resultCLSID))
disp = win32com.client.Dispatch(iptr, resultCLSID=resultCLSID)
log.debug("_pc_wrap: %s (%s)", disp.__class__.__name__, disp)
return disp
def CoCreateInstanceFromFactory(factory_ptr, iid_interface=pythoncom.IID_IDispatch, pUnkOuter=None):
"""Given a factory_ptr whose interface is IClassFactory, create the instance of clsid_class with the specified interface"""
ClassFactory = pythoncom.ObjectFromAddress(factory_ptr.value, pythoncom.IID_IClassFactory)
i = ClassFactory.CreateInstance(pUnkOuter, iid_interface)
return i
def CoCreateInstanceFromFactoryLicenced(factory_ptr, key, iid_interface=pythoncom.IID_IDispatch, pUnkOuter=None):
"""Given a factory_ptr whose interface is IClassFactory2, create the instance of clsid_class with the specified interface"""
requested_iid = _raw_guid(iid_interface)
ole_aut = WinDLL("OleAut32.dll")
key_bstr = ole_aut.SysAllocString(unicode(key))
try:
obj = IClassFactory2__CreateInstanceLic(factory_ptr, pUnkOuter or 0, c_char_p(requested_iid), key_bstr)
disp_obj = pythoncom.ObjectFromAddress(obj, iid_interface)
return disp_obj
finally:
if key_bstr:
ole_aut.SysFreeString(key_bstr)
#----------------------------------
def CoReleaseObject(obj_ptr):
"""Calls Release() on a COM object. obj_ptr should be a c_void_p"""
if not obj_ptr:
return
IUnknown__Release = WINFUNCTYPE(HRESULT)(2, 'Release', (), pythoncom.IID_IUnknown)
IUnknown__Release(obj_ptr)
#-----------------------------------
def CoCreateInstanceLicenced(clsid_class, key, pythoncom_iid_interface=pythoncom.IID_IDispatch, dwClsContext=pythoncom.CLSCTX_SERVER, pythoncom_wrapdisp=True, wrapas=None):
"""Uses IClassFactory2::CreateInstanceLic to create a COM object given a licence key."""
IID_IClassFactory2 = "{B196B28F-BAB4-101A-B69C-00AA00341D07}"
ole = OleDLL("Ole32.dll")
clsid_class_raw = _raw_guid(clsid_class)
iclassfactory2 = _raw_guid(IID_IClassFactory2)
com_classfactory = c_void_p(0)
ole.CoGetClassObject(clsid_class_raw, dwClsContext, None, iclassfactory2, byref(com_classfactory))
try:
iptr = CoCreateInstanceFromFactoryLicenced(
factory_ptr = com_classfactory,
key=key,
iid_interface=pythoncom_iid_interface,
pUnkOuter=None,
)
if pythoncom_wrapdisp:
return _pc_wrap(iptr, resultCLSID=wrapas or clsid_class)
return iptr
finally:
if com_classfactory:
CoReleaseObject(com_classfactory)
#-----------------------------------------------------------
#DLLs
def CoDllGetClassObject(dll_filename, clsid_class, iid_factory=pythoncom.IID_IClassFactory):
"""Given a DLL filename and a desired class, return the factory for that class (as a c_void_p)"""
dll = OleDLL(dll_filename)
clsid_class = _raw_guid(clsid_class)
iclassfactory = _raw_guid(iid_factory)
com_classfactory = c_void_p(0)
dll.DllGetClassObject(clsid_class, iclassfactory, byref(com_classfactory))
return com_classfactory
def CoCreateInstanceFromDll(dll, clsid_class, iid_interface=pythoncom.IID_IDispatch, pythoncom_wrapdisp=True, wrapas=None):
iclassfactory_ptr = CoDllGetClassObject(dll, clsid_class)
try:
iptr = CoCreateInstanceFromFactory(iclassfactory_ptr, iid_interface)
if pythoncom_wrapdisp:
return _pc_wrap(iptr, resultCLSID=wrapas or clsid_class)
return iptr
finally:
CoReleaseObject(iclassfactory_ptr)
def CoCreateInstanceFromDllLicenced(dll, clsid_class, key, iid_interface=pythoncom.IID_IDispatch, pythoncom_wrapdisp=True, wrapas=None):
iclassfactory2_ptr = CoDllGetClassObject(dll, clsid_class, iid_factory=IID_IClassFactory2)
try:
iptr = CoCreateInstanceFromFactoryLicenced(iclassfactory2_ptr, key, iid_interface)
if pythoncom_wrapdisp:
return _pc_wrap(iptr, resultCLSID=wrapas or clsid_class)
return iptr
finally:
CoReleaseObject(iclassfactory2_ptr)