(content)
extract all variable names from content, which is in format $variable
    @param (str) content
    @return (list) variable name list

    e.g. $variable => ["variable"]
         /blog/$postid => ["postid"]
         /$var1/$var2 => ["var1", "var2"]
         abc => []
extract all variable names from content, which is in format $variable
    @param (str) content
    @return (list) variable name list
extract all variable names from content which is in format $variable @param ( str ) content @return ( list ) variable name list
def extract_variables(content):
    """ extract all variable names from content, which is in format $variable
    @param (str) content
    @return (list) variable name list

    e.g. $variable => ["variable"]
         /blog/$postid => ["postid"]
         /$var1/$var2 => ["var1", "var2"]
         abc => []
    """
    try:
        return re.findall(variable_regexp, content)
    except TypeError:
        return []
def extract_variables ( content ) : try : return re . findall ( variable_regexp , content ) except TypeError : return [ ]