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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 get_html_filename(filename):
 """Converts the filename to a .html extension"""

    if ".html" in filename:
        newFilename = filename
    elif ".md" in filename:
        newFilename = filename.replace(".md", ".html")
    elif ".tile" in filename:
        newFilename = filename.replace(".tile", ".html")
    elif ".jade" in filename:
        newFilename = filename.replace(".jade", ".html")
    elif ".txt" in filename:
        newFilename = filename.replace(".txt", ".html")
    elif ".rst" in filename:
        newFilename = filename.replace(".rst", ".html")
    elif ".docx" in filename:
        newFilename = filename.replace(".docx", ".html")
    else:
        print(filename + " is not a valid file type!")

    return newFilename