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  • [Python] - Powerful Function
    개발/Python 2022. 7. 27. 14:12

    1. Range


    • range는 range(start, end, step) Option
    • range's result  start_number ~ end-1 collection
    list(range(5,10))
    > [5, 6, 7, 8, 9]
    list(range(10,20,2))
    > [10, 12, 14, 16, 18]

     

    2. Enumerate


    • Use repeat Loop we need to check times Loop
    • return tuple( index , element )
    for i, v in enumerate(t):
        print("index : {}, value: {}".format(i,v))
    """
    index : 0, value: 1
    index : 1, value: 5
    index : 2, value: 7
    index : 3, value: 33
    index : 4, value: 39
    index : 5, value: 52
    """

     

    3. Map


    map(function, iterable)

     

    • map is function that processes the elements of a list as a specified function
    • map do not change origin list and create new list
    # change float to int
    a = [1.2, 2.5, 3.7, 4.6]
    a = [int(i) for i in a ]
    
    # map function
    a = list(map(int,a))
    
    # int+1
    list(map(lambda x:int(x)+1 , a))

     

    4. Filter


    filter(function, iterable)
    • filter function return Elements filtered under certain conditions to iterator object
    a = [1,2,3,4]
    # filter function
    result = list(filter(lambda x : x%2==0 , a))

     

    5. Zip


    • zip function get parameter iterable object and returns iterator that can sequentially access each iterable object element 
    • Iterate over several iterables in parallel, producing tuples with an item from each one.
    • you should be aware of iterable element length. ( the data is woven based on the shortest argument, and the rest is discarded )
    numbers = [1, 2, 3]
    letters = ["A", "B", "C"]
    [pair for pair in zip(numbers, letters) ]
    > [(1, 'A'), (2, 'B'), (3, 'C')]
    
    #dict example
    keys = [1, 2, 3]
    values = ["A", "B", "C"]
    dict(zip(keys, values))
    
    # be careful
    numbers = ["1", "2", "3"]
    letters = ["A"]
    list(zip(numbers, letters))
    > [('1', 'A')]

     

    6. Divmod


    q, r = divmod(n, d)
    q, r = (n // d, n % d)

    '개발 > Python' 카테고리의 다른 글

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    [Python] - Set  (0) 2022.07.27
    [Python] - Dictionary  (0) 2022.07.27
    [Python] - Tuple  (0) 2022.07.27

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