combine multiple xml files into one (Python 2.7)

combine.py

filenames = ['M384_0201_output.xml','M384_0202_output.xml','M384_0203_output.xml','M384_0204_output.xml','M384_0205_output.xml','M384_0206_output.xml','M384_0207_output.xml','M384_0208_output.xml','M384_0209_output.xml','M384_0210_output.xml','M384_0211_output.xml','M384_0212_output.xml','M384_0213_output.xml','M384_0214_output.xml','M384_0215_output.xml','M384_0216_output.xml','M384_0217_output.xml','M384_0218_output.xml','M384_0219_output.xml','M384_0220_output.xml']
with open('m384-import-11.xml', 'w') as outfile:
    for fname in filenames:
        with open(fname) as infile:
            for line in infile:
                outfile.write(line)