关于变量
- L （Local） 局部作用域
- E （Enclosing） 闭包函数外的函数中
- G （Global） 全局作用域
- B （Built-in） 内建作用域
以 L –> E –> G –> B 的规则查找，即：在局部找不到，便会去局部外的局部找，再找不到就会去全局找，再者去内建中找。
__builtins__.a = 0 # Built-in variable
b = 1 # Global variable
def outside():
c = 2 # Enclosing variable
def inside():
d = 3 # Local variable
print(a)
print(b)
print(c)
print(d)
inside()
outside()
# 0
# 1
# 2
# 3
修改Global variable
a = 0
def outside():
b = 1
def inside():
global a # 与全局变量a指向同一个对象
a = 100
c = 2
print(a)
print(b)
print(c)
inside()
outside()
print(a)
# 100
# 1
# 2
# 100
修改Enclosing variable
a = 0
def outside():
b = 1
def inside():
nonlocal b # 与Enclosing variable b指向同一个对象
b = 10
c = 2
print(a)
print(b)
print(c)
inside()
print(b)
outside()
# 0
# 10
# 2
# 10
globals
a = 0
print(globals()) # {'a': 0 ...}
def outside():
globals()['b'] = 1
outside()
print(globals()) # {'a': 0, 'b': 1 ...}
locals
def outside():
a = 0
print(locals()) # {'a': 0}
outside()