How to fix the psycopg2 syntax error at or near '%'?

Basically trying to create ISNERT function, which will compile the insert and execute it.

def Insert(self,tablename, **kwargs):
		qms = []
		for idx, item in enumerate(kwargs):
			qms.append('%%s')
		qmarks = ', '.join(qms)
		res = []
		res.extend(kwargs.keys())
		res.extend(kwargs.values())
		res = tuple(res)
		QUERY = "INSERT INTO "+tablename+" (%s) VALUES (%s)" % (qmarks, qmarks)
		self.dc.execute(QUERY, res)
		self.db.commit()

Returns me:

psycopg2.errors.SyntaxError: syntax error at or near "%"
LINE 1: INSERT INTO users (%s, %s) VALUES (%s, %s)

psycopg2's execute() function just injects the values but not the columns, you need to pass the real column names to QUERY:

import psycopg2
import psycopg2.extras


class A():
    def __init__(self):
        self.dc = ...
        self.db = ...

    def Insert(self, tablename, **kwargs):
        columns = []
        valuePlaceholders = []
        values = []
        for column, value in kwargs.items():
            columns.append(column)
            valuePlaceholders.append('%%s')
            values.append(value)

        QUERY = "INSERT INTO " + tablename + " (%s) VALUES (%s)" % (', '.join(columns), ', '.join(valuePlaceholders))
        print(self.db.mogrify(QUERY, values))
        #self.db.execute(QUERY, values)
        #self.db.commit()


a = A().Insert('foo', arg1="bar", arg2="test")

Output:

b'INSERT INTO foo (arg1, arg2) VALUES (%s, %s)'

Your qms array is filled with the string values '%s'.
Your qmarks string then equals '%s, %s'.
After that you inject that value in your query string twice so you have 'INSERT INTO users (%s, %s) VALUES (%s, %s)'.
The issue here is that you have filled your array with incorrect values.
You need to inject your table names and values instead of %s