Global value on Python

Nice to meet you!
This is my first article in my blog.
I study Robotics at University in Japan.
So I write mainly about robots and programs.

Summary:
This page is written about global value on Python.
You have to declare a 'global' to use global variables in Python.
I show some example ,and in last describe how to use global variables in class.

I show how to use simple global variables.
You can use a global variables by declaring a 'global' in the function

g1 = 0
def gl_test1():
    global g1
　　print g1

gl_test1()

EXECUTION RESULT
0

Next I try to change the value of a global variables.
You can recognize that saved the value adding one to every call.

g2 = 0

def gl_test2():
    global g2
    g2 += 1
    print g2

for i in range(10):
    gl_test2()

EXECUTION RESULT
1
2
3
4
5
6
7
8
9
10

Last, I show example of using global variables at Class.
You can access a global variables from the class by putting 'self' as an example.
I recommend that you access to the global variables via the method.

class GlTest(object):
    g = 0
   
    def get(self):
        global g
        return self.g
　　　　　　　　
　　def add(self, x):
    　　global g
      　self.g += x

gc = GlTest()
gc.get()

EXECUTION RESULT
0

gc.add(100)
gc.get()

EXECUTION RESULT
100

Thanks you for read my page.