python-deep-dive/Scopes_Closures_Decorators/GlobalLocalScopes.py at master · maherme/python-deep-dive · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Mon Apr 26 23:25:14 2021

@author: maherme
"""
#%%

a = 10

def my_func(n):
    print('global a:', a)
    c = a ** n
    return c

res = my_func(2)
print(res)

#%%

def my_func(n):
    a = 20
    c = a ** n
    return c

print(a)
res = my_func(2)
print(res)
print(a) # a is not modified because a inside my_func is in other scope, is not global

#%%

def my_func(n):
    global a # Now a is global, it will change
    a = 20
    c = a ** n
    return c

print(a)
res = my_func(2)
print(res)
print(a)

#%%

def my_func():
    global var
    var = 'hello world'
    return

# print(var) # This will fail due to var is not defined
my_func()
print(var)

#%%

def my_func():
    global a
    a = 'hello'
    print('global a:', a)

my_func()
print(a)

#%%

a = 10

def my_func():
    print('global a:', a) # fails because a is local here, but is declared after using.
    a = 'hello world' # a is declared here
    print(a)

my_func()

#%%

for i in range(10):
    x = 2 * i

print(x) # Notice x exists outside the for loop.

#%%