# Source code for pymatgen.io.vasp.help

    """
    Get help with VASP parameters from VASP wiki.
    """

    import requests
    import re
    import urllib3

    from bs4 import BeautifulSoup

    class VaspDoc:
        """
        A VASP documentation helper.
        """

        def __init__(self):
            """
            Init for VaspDoc.
            """
            self.url_template = "http://www.vasp.at/wiki/index.php/%s"
            urllib3.disable_warnings()

        def print_help(self, tag):
            """
            Print the help for a TAG.

            Args:
                tag (str): Tag used in VASP.
            """
            print(self.get_help(tag))

        def print_jupyter_help(self, tag):
            """
            Display HTML help in ipython notebook.

            Args:
                tag (str): Tag used in VASP.
            """
            help = self.get_help(tag, "html")
            from IPython.core.display import display, HTML
            display(HTML(help))

        def get_help(self, tag, fmt="text"):
            """
            Get help on a VASP tag.

            Args:
                tag (str): VASP tag, e.g., ISYM.

            Returns:
                Help text.
            """
            tag = tag.upper()
            r = requests.get("http://www.vasp.at/wiki/index.php/%s" % tag, verify=False)
            soup = BeautifulSoup(r.text)
            main_doc = soup.find(id="mw-content-text")
            if fmt == "text":
                output = main_doc.text
                output = re.sub("\n{2,}", "\n\n", output)
            else:
                output = str(main_doc)

            return output

        def get_incar_tags(self):
            """
            Returns: All incar tags
            """
            tags = []
            for page in ["http://www.vasp.at/wiki/index.php/Category:INCAR",
                         "http://www.vasp.at/wiki/index.php?title=Category:INCAR&pagefrom=ML+FF+LCONF+DISCARD#mw-pages"]:
                r = requests.get(page, verify=False)
                soup = BeautifulSoup(r.text)
                for div in soup.findAll('div', {'class': 'mw-category-group'}):
                    children = div.findChildren('li')
                    for child in children:
                        tags.append(child.text.strip())
            return tags

    if __name__ == "__main__":
        doc = VaspDoc()
        doc.print_help("ISYM")
        print(doc.get_incar_tags())