python3.6.2 local variable def

When you declare variables within a function definition, they are not related to other variables with the same name outside the function, that is, the variable name is local to the function. This is called the scope of the variable. All variables are scoped to their defined blocks, starting with the point where their names are defined.

Using local variables

def func (x):
Print (' x is ', x)
x=2
Print (' Changed local x to ', X)
X=50
Func (x)
Print (' x is still ', X)

Output

X is 50
Changed local X to 2
X is still 50

How it works

In the function, the first time we use the value of X, Python uses the value of the formal parameter declared by the function. Next, we assign the value 2 to X. X is the local variable of the function. So, when we change the value of x within a function, the x defined in the main block is unaffected. In the last print statement, we proved that the X value in the main block is really not affected.

python3.6.2 local variable def