AssertionError when threading in Python
Question:
I’m trying to run some simple threading in Python using:
t1 = threading.Thread(analysis("samplequery"))
t1.start()
other code runs in here
t1.join()
Unforunately I’m getting the error:
“AssertionError: group argument must be none for now”
I’ve never implemented threading in Python before, so I’m a bit unsure as to what’s going wrong. Does anyone have any idea what the problem is?
I’m not sure if it’s relevant at all, but analysis is a method imported from another file.
I had one follow up query as well. Analysis returns a dictionary, how would I go about assigning that for use in the original method?
Thanks
Answers:
You want to specify the target keyword parameter instead:
t1 = threading.Thread(target=analysis("samplequery"))
You probably meant to make analysis the run target, but 'samplequery the argument when started:
t1 = threading.Thread(target=analysis, args=("samplequery",))
The first parameter to Thread() is the group argument, and it currently only accepts None as the argument.
From the threading.Thread() documentation:
This constructor should always be called with keyword arguments. Arguments are:
- group should be
None; reserved for future extension when a ThreadGroup class is implemented.
- target is the callable object to be invoked by the
run() method. Defaults to None, meaning nothing is called.
You need to provide the target attribute:
t1 = threading.Thread(target = analysis, args = ('samplequery',))
I’m trying to run some simple threading in Python using:
t1 = threading.Thread(analysis("samplequery"))
t1.start()
other code runs in here
t1.join()
Unforunately I’m getting the error:
“AssertionError: group argument must be none for now”
I’ve never implemented threading in Python before, so I’m a bit unsure as to what’s going wrong. Does anyone have any idea what the problem is?
I’m not sure if it’s relevant at all, but analysis is a method imported from another file.
I had one follow up query as well. Analysis returns a dictionary, how would I go about assigning that for use in the original method?
Thanks
You want to specify the target keyword parameter instead:
t1 = threading.Thread(target=analysis("samplequery"))
You probably meant to make analysis the run target, but 'samplequery the argument when started:
t1 = threading.Thread(target=analysis, args=("samplequery",))
The first parameter to Thread() is the group argument, and it currently only accepts None as the argument.
From the threading.Thread() documentation:
This constructor should always be called with keyword arguments. Arguments are:
- group should be
None; reserved for future extension when aThreadGroupclass is implemented.- target is the callable object to be invoked by the
run()method. Defaults toNone, meaning nothing is called.
You need to provide the target attribute:
t1 = threading.Thread(target = analysis, args = ('samplequery',))