Global static variables in Python

Question

def Input():
 c = raw_input ('Enter data1,data2: ')
 data = c.split(',')
 return data

I need to use list data in other functions, but I don't want to enter raw_input everytime. How I can make data like a global static in c++ and put it everywhere where it needed?

• tamasd: You might consider not using these kind of global variables (hard dependencies), because they can make problems with testing and separation.
• Lord British: You can use data = raw_input('Enter data1,data2: ').split(',')

Answer 1

Add the global keyword to your function:

def Input():
 global data
 c = raw_input ('Enter data1,data2: ')
 data = c.split(',')
 return data

The global data statement is a declaration that makes data a global variable. After calling Input() you will be able to refer to data in other functions.

• Lord British: If data is global do you need the line return data ?
• Arpan Saini: Python gives an error when you define global variable from a function, if define at global level it doesn't get updated from a method.

Answer 2

using global variables is usually considered bad practice. It's better to use proper object orientation and wrap 'data' in a proper class / object, e.g.

class Questionaire(object):
 def __init__(self):
 self.data = ''
 def input(self):
 c = raw_input('Enter data1, data2:')
 self.data = c.split(',')
 def results(self):
 print "You entered", self.data
q = Questionaire()
q.input()
q.results()