import re


def combine_tops(top_text, itp_texts):
    """
    Search through parent topology top_text and replace
    #include lines with the relevant child topologies
    from the dictionary itp_texts
    """
    for itp in itp_texts:
        # split on include string, then rejoin around itp file
        spl = re.split('#include ".*{}"\n'.format(itp), top_text)
        top_text = itp_texts[itp].join(spl)
    return top_text