How to pass variable by reference in Python?

Question

My code has this structure:

class Example(wx.Frame,listmix.ColumnSorterMixin):
 def __init__(self,parent):
 wx.Frame.__init__(self,parent)

 self.InitUI()

 def InitUI(self): 
 ..... 

when a button is clicked this function is called and i take the self.id_number which is a number

 def OnB(self, event):
 self.id_number = self.text_ctrl_number.GetValue()
 aa = latitude[int(self.id_number)]
 bb = longitude[int(self.id_number)]

I want to pass the variables aa and bb to a different script called application. This script by calling it with import, automatically pop up a window. I need by clicking the button that is linked with OnB definition to pop up the window from the other script as it does when i am running it alone and display lets say for example the variables aa and bb, how can I do it

Answer 1

Python provides neither pass-by-reference nor pass-by-value argument passing. Please read this for an explanation of why people sometimes think that it does, and what Python actually does instead:

http://import-that.dreamwidth.org/1130.html

To get an effect *similar* to pass-by-reference, you can wrap your variable in a list, and then only operate on the list item. For example:

one = [1]
two = [2]

def swap(a, b):
 a[0], b[0] = b[0], a[0]

swap(one, two)
print one[0], two[0]
=> will print "2 1"

But note carefully that in the swap function I do not assign directly to the arguments a and b, only to their items a[0] and b[0]. If you assign directly to a and b, you change the local variables.

# This does not work.
def swap(a, b):
 a, b = b, a

Rather than trying to fake pass-by-reference semantics, it is much better to understand Python's capabilities and learn how to use it to get the same effect. For example, instead of writing a swap procedure, it is much simpler to just do this:

one = 1
two = 2
one, two = two, one
print one, two
=> will print "2 1"

Answer 2

Technically: You cant.

I dont know your real problem but would suggest to check the following link -
http://robertheaton.com/2014/02/09/pythons-pass-by-object-reference-as-explained-by-philip-k-dick/
http://stackoverflow.com/questions/986006/python-how-do-i-pass-a-variable-by-reference
http://stackoverflow.com/questions/9696495/python-when-is-a-variable-passed-by-reference-and-when-by-value