浅谈python函数之作用域(python3.5)

def func1():
 name = 1

print(func1) # <function func1 at 0x101a03d08>
print(name)
# Traceback (most recent call last):
# File "<stdin>", line 1, in <module>
# NameError: name 'name' is not defined

test = 'global variable'

def scope_test():
 def inner():
  nonlocal test
  print(test)

scope_test() # SyntaxError: no binding for nonlocal 'test' found

def scope_test():
 def do_local():
  spam = "local spam"

 def do_nonlocal(): 
  nonlocal spam　　# 递归向上寻找上层函数命名空间中的spam变量
  spam = "nonlocal spam"

 def do_global():
  global spam # 在全局变量中寻找spam变量，没有则创建
  spam = "global spam"

 spam = "test spam"
 do_local()
 print("After local assignment:", spam) # 输出本地变量 spam
 do_nonlocal()
 print("After nonlocal assignment:", spam)
 do_global()
 print("After global assignment:", spam)

scope_test()
print("In global scope:", spam)

<SPAN style="FONT-SIZE: 14px">1 After local assignment: test spam 
After nonlocal assignment: nonlocal spam 
After global assignment: nonlocal spam 
In global scope: global spam 
</SPAN>

def fn():
  a = 1
  def closure():
    nonlocal a
    a += 1
    print(a)
  return closure

inner = fn() 
print(inner.__closure__)  # (<cell at 0x10240b408: int object at 0x100277bc0>,)
inner() # 2
inner() # 3

a = 1
def local_test():
  a += 1
  print(a)
local_test()  # UnboundLocalError: local variable 'a' referenced before assignment

print(b)  # NameError: name 'b' is not defined

name = "lzl"
 
def f1():
  print(name)
 
def f2():
  name = "eric"
  f1()
 
f2() # lzl

lambda x: x + 1
# 函数功能类型于下面的函数
def _(x):
  return x + 1

li = [lambda :x for x in range(10)]
print(li[0]())

def fn():
  return x 

li = []
for x in range(10):
  li.append(fn)
li[0]() # fn() -> 9，根据变量搜索规则，x在函数中没有定义，在全局变量中查找