cython

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# mode: run
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# tag: del, slicing
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def del_constant_start_stop(x):
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    """
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    >>> l = [1,2,3,4]
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    >>> del_constant_start_stop(l)
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    [1, 2]
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    >>> l = [1,2,3,4,5,6,7]
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    >>> del_constant_start_stop(l)
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    [1, 2, 7]
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    """
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    del x[2:6]
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    return x
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def del_start(x, start):
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    """
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    >>> l = [1,2,3,4]
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    >>> del_start(l, 2)
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    [1, 2]
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    >>> l = [1,2,3,4,5,6,7]
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    >>> del_start(l, 20)
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    [1, 2, 3, 4, 5, 6, 7]
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    >>> del_start(l, 8)
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    [1, 2, 3, 4, 5, 6, 7]
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    >>> del_start(l, 4)
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    [1, 2, 3, 4]
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    >>> del_start(l, -2)
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    [1, 2]
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    >>> l
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    [1, 2]
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    >>> del_start(l, -2)
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    []
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    >>> del_start(l, 2)
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    []
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    >>> del_start(l, -2)
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    []
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    >>> del_start(l, 20)
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    []
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    >>> del_start([1,2,3,4], -20)
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    []
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    >>> del_start([1,2,3,4], 0)
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    []
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    """
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    del x[start:]
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    return x
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def del_stop(x, stop):
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    """
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    >>> l = [1,2,3,4]
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    >>> del_stop(l, 2)
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    [3, 4]
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    >>> l = [1,2,3,4,5,6,7]
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    >>> del_stop(l, -20)
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    [1, 2, 3, 4, 5, 6, 7]
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    >>> del_stop(l, -8)
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    [1, 2, 3, 4, 5, 6, 7]
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    >>> del_stop(l, -4)
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    [4, 5, 6, 7]
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    >>> del_stop(l, -2)
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    [6, 7]
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    >>> l
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    [6, 7]
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    >>> del_stop(l, -2)
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    [6, 7]
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    >>> del_stop(l, 2)
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    []
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    >>> del_stop(l, -2)
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    []
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    >>> del_stop(l, 20)
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    []
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    >>> del_stop([1,2,3,4], -20)
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    [1, 2, 3, 4]
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    >>> del_stop([1,2,3,4], 0)
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    [1, 2, 3, 4]
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    """
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    del x[:stop]
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    return x
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def del_start_stop(x, start, stop):
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    """
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    >>> l = [1,2,3,4]
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    >>> del_start_stop(l, 0, 2)
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    [3, 4]
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    >>> l
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    [3, 4]
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    >>> l = [1,2,3,4,5,6,7]
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    >>> del_start_stop(l, -1, -20)
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    [1, 2, 3, 4, 5, 6, 7]
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    >>> del_start_stop(l, -20, -8)
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    [1, 2, 3, 4, 5, 6, 7]
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    >>> del_start_stop(l, -6, -4)
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    [1, 4, 5, 6, 7]
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    >>> del_start_stop(l, -20, -2)
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    [6, 7]
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    >>> l
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    [6, 7]
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    >>> del_start_stop(l, -2, 1)
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    [7]
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    >>> del_start_stop(l, -2, 3)
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    []
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    >>> del_start_stop(l, 2, 4)
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    []
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    >>> del_start_stop([1,2,3,4], 20, -20)
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    [1, 2, 3, 4]
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    >>> del_start_stop([1,2,3,4], 0, 0)
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    [1, 2, 3, 4]
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    """
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    del x[start:stop]
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    return x
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