Circular invocation of Python functions

 1  def   Foo ():  2   '  

Directly on the script, the above script if replaced by the C language code, the Foo function must be added to a bar function declaration, but not in Python, because the Foo function is not called before the bar function is not valid, until the bar function is called, The bar function has been declared so it can be found.

So Python also supports circular invocation, a call B, and a. The effect of the operation is to put the line stacks the top dead. Code Run Effect:

Circular invocation of Python functions