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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 regrep(filename, patterns, reverse=False, terminate_on_match=False, postprocess=str):
 """ A powerful regular expression version of grep. Args: filename (str):
 Filename to grep. patterns (dict):
 A dict of patterns, e.g., {"energy": "energy\(sigma->0\)\s+=\s+([\d\-\.]+)"}. reverse (bool):
 Read files in reverse. Defaults to false. Useful for large files, especially when used with terminate_on_match. terminate_on_match (bool):
 Whether to terminate when there is at least one match in each key in pattern. postprocess (callable):
 A post processing function to convert all matches. Defaults to str, i.e., no change. Returns: A dict of the following form: For reverse reads, the lineno is given as a -ve number. Please note that 0-based indexing is used. """

    compiled = {k: re.compile(v) for k, v in patterns.items()}
    matches = collections.defaultdict(list)
    gen = reverse_readfile(filename) if reverse else zopen(filename, "rt")
    for i, l in enumerate(gen):
        for k, p in compiled.items():
            m = p.search(l)
            if m:
                matches[k].append([[postprocess(g) for g in m.groups()],
                                   -i if reverse else i])
        if terminate_on_match and all([
                len(matches.get(k, [])) for k in compiled.keys()]):
            break
    try:
        # Try to close open file handle. Pass if it is a generator.
        gen.close()
    except:
        pass
    return matches