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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 parse(path):
 """ Parses xml and returns a formatted dict. Example: wpparser.parse("./blog.wordpress.2014-09-26.xml") Will return: { "blog": { "tagline": "Tagline", "site_url": "http://marteinn.se/blog", "blog_url": "http://marteinn.se/blog", "language": "en-US", "title": "Marteinn / Blog" }, "authors: [{ "login": "admin", "last_name": None, "display_name": "admin", "email": "martin@marteinn.se", "first_name": None} ], "categories": [{ "parent": None, "term_id": "3", "name": "Action Script", "nicename": "action-script", "children": [{ "parent": "action-script", "term_id": "20", "name": "Flash related", "nicename": "flash-related", "children": [] }] }], "tags": [{"term_id": "36", "slug": "bash", "name": "Bash"}], "posts": [{ "creator": "admin", "excerpt": None, "post_date_gmt": "2014-09-22 20:10:40", "post_date": "2014-09-22 21:10:40", "post_type": "post", "menu_order": "0", "guid": "http://marteinn.se/blog/?p=828", "title": "Post Title", "comments": [{ "date_gmt": "2014-09-24 23:08:31", "parent": "0", "date": "2014-09-25 00:08:31", "id": "85929", "user_id": "0", "author": u"Author", "author_email": None, "author_ip": "111.111.111.111", "approved": "1", "content": u"Comment title", "author_url": "http://example.com", "type": "pingback" }], "content": "Text", "post_parent": "0", "post_password": None, "status": "publish", "description": None, "tags": ["tag"], "ping_status": "open", "post_id": "828", "link": "http://www.marteinn.se/blog/slug/", "pub_date": "Mon, 22 Sep 2014 20:10:40 +0000", "categories": ["category"], "is_sticky": "0", "post_name": "slug" }] } """


    doc = ET.parse(path).getroot()

    channel = doc.find("./channel")

    blog = _parse_blog(channel)
    authors = _parse_authors(channel)
    categories = _parse_categories(channel)
    tags = _parse_tags(channel)
    posts = _parse_posts(channel)

    return {
        "blog": blog,
        "authors": authors,
        "categories": categories,
        "tags": tags,
        "posts": posts,
    }