Global keyword is a keyword that allows a user to modify a variable outside of the current scope. It is used to create global variables from a non-global scope i.e inside a function.
It is used to create a global variable and make changes to the variable in a local context. It is not needed for printing and accessing.
Rules of global Keyword
- If a variable is assigned a value anywhere within the function’s body, it’s assumed to be a local. When we define a variable outside of a function, it is global by default. We don't have to use
globalkeyword to define it.
- We use
globalkeyword to read and write a global variable inside a function
- There is no need to use
globalkeyword outside a function.
Use of global keyword
a = 3 def func_1(): a = a**5 print(a) func_1()
Output: UnboundLocalError: local variable 'a' referenced before assignment.
This output is an error because we are trying to assign a value to a variable in an outer scope.
a = 3 def func_1(): global a a = a**5 print(a) func_1()
Now we declare the variable inside the function along with the keyword global. This makes the variable modifiable.