def read_requirements_file(filename):
    """Read requirements file and extract a set of library requirements.

    Parameters
    ----------
    filename : `str`
        Filename of requirements file.

    Returns
    -------
    requirements : array_like(`str`, ndim=1)
        Extracted set of library requirements.
    """
    with open(filename, 'r') as file_obj:
        requirements = file_obj.readlines()

    requirements = [line.strip() for line in requirements if line.strip()]
        
    return requirements