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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 copy_or_replace(src, dst):
    '''try to copy with mode, and if it fails, try replacing
    '''
    try:
        shutil.copy(src, dst)
    except (OSError, IOError), e:
        # It's possible that the file existed, but was owned by someone
        # else - in that situation, shutil.copy might then fail when it
        # tries to copy perms.
        # However, it's possible that we have write perms to the dir -
        # in which case, we can just delete and replace
        import errno

        if e.errno == errno.EPERM:
            import tempfile
            # try copying into a temporary location beside the old
            # file - if we have perms to do that, we should have perms
            # to then delete the old file, and move the new one into
            # place
            if os.path.isdir(dst):
                dst = os.path.join(dst, os.path.basename(src))

            dst_dir, dst_name = os.path.split(dst)
            dst_temp = tempfile.mktemp(prefix=dst_name + '.', dir=dst_dir)
            shutil.copy(src, dst_temp)
            if not os.path.isfile(dst_temp):
                raise RuntimeError(
                    "shutil.copy completed successfully, but path"
                    " '%s' still did not exist" % dst_temp)
            os.remove(dst)
            shutil.move(dst_temp, dst)