Has been using python function in parentheses, could not tell a bit, in the end when to use parentheses, brackets when not to, caused great confusion.
Results of the:
According to the results to analyze:
1, x = aaa aaa is a class name, not behind brackets, print the results, it indicates that x is a class
2, the absence of brackets, not instantiating the class, the result y is public property, so as xy print you
. 3, as a function foo aaa class, method or property referred to, but has not foo brackets behind, the print result as an address in memory foo
Notice that the print (x.foo ()), or print (x.foo ( 'aa')) are given,
Thus, according to the prompts, foo should be followed with two parameters, here why it should take two parameters. Because there is no initialization x, x is not passed as a parameter in the function foo
and so
As can be seen, herein it refers to a class itself self
4, x = aaa () class parentheses behind aaa, aaa print result class memory address
5, since x = aaa () indicates aaa is instantiated, therefore call the constructor of y, the printed result is the value self.y
6 shows a method foo class, foo without parentheses, the function is not executed.
And 7. 8, foo parentheses, perform the function foo. Here foo with only one parameter in the "u" or "cc", and not with two parameters mentioned above, since aaa instantiated
So he concludes.
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类带括号，类实例化，
函数带括号，执行函数，返回函数的结果
否则不执行，只是调用类或函数本身。
觉得文章还可以的话不妨收藏起来慢慢看，有任何意见或者看法欢迎大家评论！