how to run python/djanjo shell as a script - python-3.x

Question

In a tutorial on django we create a simple table run migrations and then go into a shell with the command:
python manage.py shell
from there, in the shell we run the following:
from flights.models import Flight
f = Flight(origin="New York", destination="london", duration=415)
f.save()
I'm trying to figure out how to run these commands from a py file so I created test.py:
from flights.models import Flight
f=Flight(origin="New York",destination="London", duration=415)
f.save()
but get the error Models aren't loaded. How to resolve? I'm definitely a little confused. I am able to update the database from a web served page with the following in my views.py file:
from django.shortcuts import render
from flights.models import Flight
def index(request):
f=Flight(origin="New York",destination="London", duration=415)
f.save()
return render(request, "flights/index.html", {
})
What I am asking is how to update the database directly on the backend. Do I just use standard python sql commands? For instance:
import sqlite3
from sqlite3 import Error
import csv
def sql_connection(db_file):
""" create a database connection to the SQLite database
specified by db_file
:param db_file: database file
:return: Connection object or None
"""
conn = None
try:
conn = sqlite3.connect(db_file)
return conn
except Error as e:
print(e)
return conn
def sql_create(conn, create_table_sql):
""" create a table from the create_table_sql statement
:param conn: Connection object
:param create_table_sql: a CREATE TABLE statement
:return:
"""
try:
c = conn.cursor()
c.execute(create_table_sql)
except Error as e:
print(e)
def sql_insert(conn,sql,data,single):
cur=conn.cursor()
if single:
cur.execute(sql,data)
rowCount = cur.lastrowid
else:
cur.executemany(sql,data)
rowCount = cur.rowcount
conn.commit()
return(rowCount)
def sql_select(conn,sql,data):
cur = conn.cursor()
cur.execute(sql,data)
rows = cur.fetchall()
return rows
def sql_update(conn,sql,data):
cur = conn.cursor()
cur.execute(sql,data)
conn.commit()
def sql_delete(conn,sql,mydata):
print(mydata)
cur = conn.cursor()
cur.execute(sql,mydata)
conn.commit()
def main():
insert = False
db_file = r"/home/saltydog/Database/crud.db"
# create a database connection
conn = sql_connection(db_file)
# create tables
sql_create_price_table = """ CREATE TABLE IF NOT EXISTS prices (
ticker text NOT NULL,
ymd integer,
price real,
PRIMARY KEY(ticker,ymd)
); """
sql_create_price2_table = """ CREATE TABLE IF NOT EXISTS prices2 (
ticker text NOT NULL,
ymd integer,
price real,
PRIMARY KEY(ticker,ymd)
); """
if conn is not None:
# create projects table
sql_create(conn, sql_create_price_table)
sql_create(conn, sql_create_price2_table)
conn.commit()
else:
print("Error! cannot create the database connection.")
if(insert):
sql_insert_record = """insert into prices(ticker,ymd,price)
values(?, ?, ?)"""
cnt = 0
with open('ibm.txt') as f:
reader = csv.reader(f)
for row in reader:
ticker = row[0]
ymd = row[1]
price = row[2]
data = (ticker, ymd, price)
if cnt != 0:
rowid = sql_insert(conn,sql_insert_record,data,True)
print(rowid)
cnt+=1
sql_insert_records = """insert into prices2(ticker,ymd,price)
values(?, ?, ?)"""
data=[]
cnt=0
with open('ibm.txt') as f:
reader = csv.reader(f)
for row in reader:
ticker = row[0]
ymd = row[1]
price = row[2]
if cnt != 0:
data.append((ticker, ymd, price))
cnt+=1
rowid = sql_insert(conn,sql_insert_records,data,False)
print(rowid)
select_records = """select ticker,ymd,price from prices
where ticker = ?
group by price
order by price"""
data=('IBM', )
rows = sql_select(conn,select_records,data)
for row in rows:
print(row)
select_records = """select ticker,ymd,price from prices
where ticker = ?
and price > ?"""
data=('IBM',100.0)
rows = sql_select(conn,select_records,data)
for row in rows:
print(row)
select_records = """select ticker,ymd,price from prices
where ymd = ?"""
data=(19990527, )
rows = sql_select(conn,select_records,data)
for row in rows:
print(row)
sql_update_records = """update prices
set price = ?
where ymd = ?"""
data = (200.00,19990527)
sql_update(conn,sql_update_records,data)
sql_delete_record = """delete from prices where ymd = ?"""
mydata = (19990528, )
sql_delete(conn,sql_delete_record,mydata)
if __name__ == '__main__':
main()