# 闭包
# 保存外层函数 环境
def clo_cur():
a =25
b =1
def cur(x):
result = a*x*x+b
return result
return cur
a =10 # 闭包会优先使用用包裹里面的数据
f = clo_cur()
print(f.__closure__)
print(f.__closure__[0].cell_contents)
print(f.__closure__[1].cell_contents)
print(type(f))
print(f(2))
# 闭包 函数+变量
# 保存上一级变量
def col_step_count():
count =0
def step_count(number):
nonlocal count# 要指定不是本地变量，否则会报错
new_count = count + number
count = new_count
return new_count
return step_count
f = col_step_count()
print(f.__closure__[0].cell_contents)
print(f(3))
print(f.__closure__[0].cell_contents)
print(f(5))
print(f.__closure__[0].cell_contents)
Lamaba匿名函数
print(f.__closure__[0].cell_contents)
# lambda paramaters: expression
f =lambda x,y : x+y
print(f(1,2))
Map
# map(def,*)
List_x = [1, 2, 3, 4, 5, 6, 7, 8, 9]
List_y = [1, 2, 3, 4, 5, 6, 7, 8, 9]
r =list(map(lambda x,y: x*x+y, List_x, List_y))
print(r)
Reduce
# reduce 用来做连续运算
from functoolsimport reduce
step = [(-1, 2), (0, 3), (1, 5)]
r = reduce(lambda x, y: (x[0]+y[0], x[1]+y[1]), step)
print(list(r))
Filter
# filter 过滤器，lambda 表达式（函数）返回bool，从而进行过滤
# 例 筛选出小写字母
alp = ['a', 'b', 'A', 'B']
r =filter(lambda x: x >'Z', alp)
print(list(r))
