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  • python 基础 2.7 range与xrange的区别

    #/usr/bin/python 
    #coding=utf-8
    #@Time :2017/10/25 19:22
    #@Auther :liuzhenchuan
    #@File :range与xrange的区别.py

    示例1:range()打开时占用内存
    #range生成一个list ,xrange是一个生成器 #range([start,] stop[, step]),
    根据start与stop指定的范围以及step设定的步长,生成一个序列
    print range(5) 
    print range(1,5)
    print range(1,5,2)
    >>> [0, 1, 2, 3, 4]
       [1, 2, 3, 4]
       [1, 3]

    示例2: xrange()不占用内存,大文件打开用xrange().
    a = xrange(5)
    print a
    print list(a)
    >>> xrange(5)
      [0, 1, 2, 3, 4]

    b = xrange(1,5) 
    print b
    print list(b)
    >>> xrange(1, 5)
    [1, 2, 3, 4]

    c = xrange(1,5,2) 
    print c
    print list(c)
    >>> xrange(1, 5, 2)
    [1, 3]
    
    
    
    
     
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  • 原文地址:https://www.cnblogs.com/lzcys8868/p/7731915.html
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