Sanitizing project name base on path

utils.py

"""
Sanitizing filename

from: https://github.com/pypa/pipenv/blob/master/pipenv/project.py
"""
    def virtualenv_name(self):
        # Replace dangerous characters into '_'. The length of the sanitized
        # project name is limited as 42 because of the limit of linux kernel
        #
        # 42 = 127 - len('/home//.local/share/virtualenvs//bin/python2') - 32 - len('-HASHHASH')
        #
        #      127 : BINPRM_BUF_SIZE - 1
        #       32 : Maximum length of username
        #
        # References:
        #   https://www.gnu.org/software/bash/manual/html_node/Double-Quotes.html
        #   http://www.tldp.org/LDP/abs/html/special-chars.html#FIELDREF
        #   https://github.com/torvalds/linux/blob/2bfe01ef/include/uapi/linux/binfmts.h#L18
        sanitized = re.sub(r'[ $`!*@"\\\r\n\t]', '_', self.name)[0:42]

        # Hash the full path of the pipfile
        hash = hashlib.sha256(self.pipfile_location.encode()).digest()[:6]
        encoded_hash = base64.urlsafe_b64encode(hash).decode()

        # If the pipfile was located at '/home/user/MY_PROJECT/Pipfile',
        # the name of its virtualenv will be 'my-project-wyUfYPqE'
        return sanitized + '-' + encoded_hash