Note the usage of function default values in python. Default Value in python

Note the usage of function default values in python. Default Value in python

When the default value is defined in the function, the value Initialization is performed only once, that is, when def methodname is executed. See the following code:

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from datetime import datetime def test(t=datetime.today()):　　print t if __name__ == "__main__":　　test()　　test()

The output time of the two method calls is the same value, rather than the current execution time. In this case, we recommend that you use the following method:

from datetime import datetime  def test2(t = None):    if t is None:        t = datetime.today()    print t if __name__ == "__main__":    test()    test()