Why indentation is important in Python and what is the scope of a global variable?

Normally, in every programming language we should normally use indentation in order to have a nice style and a readable code. But Python programs are structured through indentation, so different code blocks are defined by indentation. This indentation makes the code easier to read and understand. So all statements that are indexed with the same number of lines are part of the same code blocks.
A global variable in Python is the variable which is declared and defined outside a function.For example:def printing(): print variable

#Here we have the global scope defined variable = "I love python" printing()

#This code will print: I love python
But now, if we want to declare a varible with the same name as the global one, we have the following:
def printing(): variable = "I like python" print variable

#Here we have the global scope defined variable = "I love python" printing() print variable

#This code will output "I like python" and the "I love python" because they are completely different variables (in different scopes) but with the same name