py-day4 python filter函数

filter函数：遍历序列中的每个元素，判断每个元素得到布尔值，如果是True则留下

# 例子：条件筛选
name =['m_xiaoli','zhangfei','m_xiaoma','m_wangyun']
ret = []
def test(name):
    for i in name:
        if not i.startswith("m"):
            ret.append(i)
    return ret
print(test(name))

['zhangfei']

def test1(array):       # (最好不要用全局变量，自己定义一个变量如左)
    for i in array:
        if not i.startswith("m"):
            ret.append(i)
    return ret
print(test1(name))

['zhangfei']

# 在写程序时尽量不要把函数写死，
name =['xiaoli_d','zhangfei','xiaoma_d','m_wangyun']
ret = []
def qu_d(n):　　　　　　　　　　　　# 定义灵活的函数
    return n.endswith('_d')
def qu_m(w):
    return w.startswith('m_')
def test(func,array):
    for i in array:
        if not func(i):
            ret.append(i)
    return ret
ret = test(qu_d,name)

ref = []
def test2(func2,array2):
    for p in array2:
        if not func2(p):
            ref.append(p)
    return ref
ref = test2(qu_m,name)

print('不是_d结尾的：',ret)
print('不是m_开头的：',ref)

不是_d结尾的： ['zhangfei', 'm_wangyun']
不是m_开头的： ['xiaoli_d', 'zhangfei', 'xiaoma_d']

 #不定义，用lamnda函数也可以
name =['xiaoli_d','zhangfei','xiaoma_d','m_wangyun']
ret = []
def test(func,array):
    for i in array:
        if not func(i):
            ret.append(i)
    return ret
ret = test(lambda i:i.endswith('_d'),name)
print('不是_d结尾的：', ret)

不是_d结尾的： ['zhangfei', 'm_wangyun']

# 终极版 filter函数
name =['xiaoli_d','zhangfei','xiaoma_d','m_wangyun']
ret = []
def test(func,array):
    for i in array:
        if not func(i):
            ret.append(i)
    return ret
ret = filter(lambda i:not i.endswith('_d'),name)
print('不是_d结尾的：',list(ret))

不是_d结尾的： ['zhangfei', 'm_wangyun']