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  • 关于tuple 和 list 看点基础的东东

    当大量数据时,尽量用tuple
    print 80*'-'

    print sys.getsizeof(objiect)

    print dir(sys)
    print help(sys.getsizeof)

    tuple 的快速写法:
    test1 = 1,
    test2 = 1
    test3 = 1,2,3

    a = test3[0]
    b = test3[1]
    a, b, c = test3

    list: ['append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']
    tuple: ['count', 'index']

    所以 list 占用内存多
    imagine working with a data set containing 100 million lists or tuples, the bytes quickly add up

    另外,list 可变, tuple 不可变immutable
    once you make a tuple, it is set in stone

    tuples 比 list 更快创建
    tuples can be made more quickly than lists

    import sys
    
    print dir(sys)
    
    print help(sys.getsizeof)
    
    '''
    getsizeof(...)
        getsizeof(object, default) -> int
        
        Return the size of object in bytes.
    '''
    
    list_eg = [1,2,3,"a","b","c",True,3.14159]
    tuple_eg =(1,2,3,"a","b","c",True,3.14159)
    
    
    print "List size = ", sys.getsizeof(list_eg)
    print "tuple size = ", sys.getsizeof(tuple_eg)
    

    import timeit
    
    list_test = timeit.timeit(stmt = "[1,2,3,4,5]", number = 1000000)
    tuple_test = timeit.timeit(stmt = "(1,2,3,4,5)", number = 1000000)
    
    print "List time: ", list_test
    print "Tuple time: ", tuple_test
    

    test1 = 1,
    test2 = 1
    test3 = 1,2,3
    
    print test1
    print test2
    print test3
    
    a, b ,c = test3
    print a,b,c
    
    d = test2
    print d
    

    还有个 横线写法,我都是按一串 -----

    print dir(prime_numbers)
    
    print 80 * "-"
    
    print dir(perfect_squares)
    
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  • 原文地址:https://www.cnblogs.com/vivivi/p/13196460.html
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