python | python中的filter函数和map函数

python中的filter函数和map函数

filter()

filter()用于对容器中的元素进行过滤处理

# coding=utf-8
# 提供过滤条件函数
def f1(x):
    return x > 50
    
data1 = [66, 15, 91, 28, 98, 50, 7, 90, 99]
filtered = filter(f1, data1)
data2 = list(filtered)
print(data2)


# lambda实现
data1 = [66, 15, 91, 28, 98, 50, 7, 90, 99]
filtered = filter(lambda x : (x > 50), data1)
data2 = list(filtered)
print(data2)

map()

map()用于对容器中的元素进行映射或变换

# coding=utf-8
# 提供变换规则的函数
def f1(x):
    return x * 2

data1 = [66, 15, 91, 28, 98, 50, 7, 90, 99]
mapped = map(f1, data1)
data2 = list(mapped)
print(data2)


# lambda实现
data1 = [66, 15, 91, 28, 98, 50, 7, 90, 99]
mapped = map(lambda x : (x * 2), data1)
data2 = list(mapped)
print(data2)