To explore the code is to discover conventions, perhaps this may help
frappe@ubuntu:~/frappe-bench$ find . -name '*.py' | xargs grep item_price
[snip]
./apps/erpnext/erpnext/stock/get_item_details.py:def insert_item_price(args):
./apps/erpnext/erpnext/stock/get_item_details.py: item_price = frappe.get_doc({
./apps/erpnext/erpnext/stock/get_item_details.py: item_price = frappe.get_doc('Item Price', name)
./apps/erpnext/erpnext/stock/get_item_details.py: item_price.price_list_rate = price_list_rate
./apps/erpnext/erpnext/stock/get_item_details.py: item_price.save()
./apps/erpnext/erpnext/stock/get_item_details.py: item_price.insert()
frappe@ubuntu:~/frappe-bench$ bench mysql
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 186615
Server version: 10.2.13-MariaDB-10.2.13+maria~xenial-log mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [d56cb677eaab3383]> desc `tabItem Price`;
+------------------+---------------+------+-----+----------+-------+
| Field | Type | Null | Key | Default | Extra |
+------------------+---------------+------+-----+----------+-------+
| name | varchar(140) | NO | PRI | NULL | |
| creation | datetime(6) | YES | | NULL | |
| modified | datetime(6) | YES | | NULL | |
| modified_by | varchar(140) | YES | | NULL | |
| owner | varchar(140) | YES | | NULL | |
| docstatus | int(1) | NO | | 0 | |
| parent | varchar(140) | YES | MUL | NULL | |
| parentfield | varchar(140) | YES | | NULL | |
| parenttype | varchar(140) | YES | | NULL | |
| idx | int(8) | NO | | 0 | |
| price_list_rate | decimal(18,6) | NO | | 0.000000 | |
| selling | int(1) | NO | | 0 | |
| item_name | varchar(140) | YES | | NULL | |
| _assign | text | YES | | NULL | |
| price_list | varchar(140) | YES | | NULL | |
| item_code | varchar(140) | YES | MUL | NULL | |
| currency | varchar(140) | YES | | NULL | |
| _liked_by | text | YES | | NULL | |
| _comments | text | YES | | NULL | |
| buying | int(1) | NO | | 0 | |
| _user_tags | text | YES | | NULL | |
| item_description | text | YES | | NULL | |
+------------------+---------------+------+-----+----------+-------+
22 rows in set (0.00 sec)