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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pbc_diff(fcoords1, fcoords2):
 """ Returns the 'fractional distance' between two coordinates taking into account periodic boundary conditions. Args: fcoords1: First set of fractional coordinates. e.g., [0.5, 0.6, 0.7] or [[1.1, 1.2, 4.3], [0.5, 0.6, 0.7]]. It can be a single coord or any array of coords. fcoords2: Second set of fractional coordinates. Returns: Fractional distance. Each coordinate must have the property that abs(a) <= 0.5. Examples: pbc_diff([0.1, 0.1, 0.1], [0.3, 0.5, 0.9]) = [-0.2, -0.4, 0.2] pbc_diff([0.9, 0.1, 1.01], [0.3, 0.5, 0.9]) = [-0.4, -0.4, 0.11] """

    fdist = np.subtract(fcoords1, fcoords2)
    return fdist - np.round(fdist)