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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 check_need_install():
 """Check if installed package are exactly the same to this one. By checking md5 value of all files. """

    need_install_flag = False
    for root, _, basename_list in os.walk(SRC):
        if os.path.basename(root) != "__pycache__":
            for basename in basename_list:
                src = os.path.join(root, basename)
                dst = os.path.join(root.replace(SRC, DST), basename)
                if os.path.exists(dst):
                    if md5_of_file(src) != md5_of_file(dst):
                        return True
                else:
                    return True
    return need_install_flag