Python3 zip,lambda,map,reduce的使用

使用Python进行数据处理的时候经常遇到一些Python独有的小函数，使用这些小函数
可以大大减少代码量。Python2中的使用方法与3有些不同，具体参见
这里写链接内容

# -*- coding: utf-8 -*-"""Created on Wed Oct 26 11:51:32 2016@author: Jian"""import functoolsa = [1,2,3,4,5]b = [2,2,9,0,9]def pick_the_largest(a, b):    result = []  # A list of the largest values    # Assume both lists are the same length    list_length = len(a)    for i in range(list_length):        result.append(max(a[i], b[i]))    return resultprint(pick_the_largest(a, b))"""This function takes two equal-length collections, and merges them together in pairs.  If we use this on our list of values, we get the following: [2, 2, 9, 4, 9]"""print(list(zip(a,b)))"""function 参数：返回值"""f = lambda x, y : x + yprint(f(1,1))"""map(func,seq)func是计算的函数，seq是传入的数组"""def fahrenheit(T):     return ((float(9)/5)*T + 32)def celsius(T):     return (float(5)/9)*(T-32)temperatures = (36.5, 37, 37.5, 38, 39)F = map(fahrenheit, temperatures)C = map(celsius, F)temperatures_in_Fahrenheit = list(map(fahrenheit, temperatures))temperatures_in_Celsius = list(map(celsius, temperatures_in_Fahrenheit))print(temperatures_in_Fahrenheit)print(temperatures_in_Celsius)"""map lambda 配合使用效果更好"""C = [39.2, 36.5, 37.3, 38, 37.8] F = list(map(lambda x: (float(9)/5)*x + 32, C))print(F)"""lambda 写计算函数，a,b传入两个数组参数[18, 14, 14, 14]"""a = [1,2,3,4]b = [17,12,11,10]c = [-1,-4,5,9]print(list(map(lambda x,y:x+y, a,b)))"""filter(function, sequence) 返回True的数进数组"""fibonacci = [0,1,1,2,3,5,8,13,21,34,55]odd_numbers = list(filter(lambda x: x % 2, fibonacci))print(odd_numbers)"""113102"""print(functools.reduce(lambda x,y: x+y, [47,11,42,13]))#累加from functools import reduce#找到最大值f = lambda a,b: a if (a > b) else bprint(reduce(f, [47,11,42,102,13]))#累乘print(reduce(lambda x, y: x*y, range(1,3)))m = list(range(1,3))#[1, 2]print(m)