def merge_otu_metadata(otu_table, metadata_file, outfile, normalize=False):
    """ Use the merge python script from maaslin to merge
        the otu_table and the metadata into a single file.
        

    :param otu_table: String; file of the tsv format (not formatted by qiime)

    :param metadata_file: String; file of metadata in tsv format

    :param outfile: String; file that is a merge of the otu and metadata

    External dependencies
      - Maaslin: https://bitbucket.org/biobakery/maaslin
        
    """

    cmd="merge_metadata.py "
    if not normalize:
        cmd += " -n "

    cmd += metadata_file + " < " + otu_table + " > " + outfile

    return {
        "name": "merge_otu_metadata: " + otu_table,
        "actions": [cmd],
        "file_dep": [otu_table, metadata_file],
        "targets": [outfile]
    }