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pythonmultithreadingpython-2.7python-multithreadingkeyword-argument

Pass keyword arguments to target function in Python threading.Thread


I want to pass named arguments to the target function, while creating a Thread object.

Following is the code that I have written:

import threading

def f(x=None, y=None):
    print x,y

t = threading.Thread(target=f, args=(x=1,y=2,))
t.start()

I get a syntax error for "x=1", in Line 6. I want to know how I can pass keyword arguments to the target function.


Solution

  • t = threading.Thread(target=f, kwargs={'x': 1,'y': 2})
    

    this will pass a dictionary with the keyword arguments' names as keys and argument values as values in the dictionary. the other answer above won't work, because the "x" and "y" are undefined in that scope.

    another example, this time with multiprocessing, passing both positional and keyword arguments:

    the function used being:

    def f(x, y, kw1=10, kw2='1'):
        pass
    

    and then when called using multiprocessing:

    p = multiprocessing.Process(target=f, args=('a1', 2,), kwargs={'kw1': 1, 'kw2': '2'})