SimonCode/python/headFirst/function/ReduceFunction.py at master · SimLi/SimonCode · GitHub

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"""reduce把一个函数作用在一个序列[x1, x2, x3, ...]上，这个函数必须接收两个参数，reduce把结果继续和序列的下一个元素做

对应的函数运算"""

from functools import reduce

def sum(x, y):

return x + y

def test_reduce():

it = [1,2,3,4,5,6]

return reduce(sum,it)

print(test_reduce())

"""首字母转大写，其余小写"""

def normalize(name):

return name[:1].upper() + name[1:].lower()

"""列表推导实现，首字母大写"""

def normalizeList(list_name):

return [names[:1].upper() + names[1:].lower() for names in list_name]

names=["Admin","SIMON","zCZAi"]

print(list(map(normalize,names)))

print(normalizeList(names))

def prod(_list):

"""

列表乘积

:param _list: 数字型

:return: 返回列表乘积

"""

return reduce(lambda x,y: x*y, _list)

print(prod([1,2,3,4,5]))

def str2float(str):

"""字符串转化为浮点数"""

DIGITS = {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}

# return reduce(lambda x, y: x * 10 + y, map(lambda s: DIGITS[s], str.replace(".", ""))) / (10 * len())

return reduce(lambda x, y: x * 10 + y, map(lambda s: DIGITS[s], str.replace('.', ''))) / pow(10,len(str)-str.index('.')-1)

print(str2float("123.456"))

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