I got this "ValueError: invalid literal for int() with base 10" in my Django project

Question

model in my application:

from __future__ import unicode_literals
from django.db import models

class Category(models.Model):
    name = models.CharField(max_length = 128, unique = True)
    def __unicode__(self):
        return self.name

class ModelName(models.Model):
    name = models.CharField(max_length = 128, unique = True)

    def __unicode__(self):
        return self.name

class CarStorage(models.Model):
    category = models.ForeignKey(Category)
    CarID = models.CharField(max_length = 10, unique = True, null = False)
    model = models.ForeignKey(ModelName)
    storage = models.IntegerField(default = 0)
    perchasedYear = models.IntegerField(default = 0)

    def __unicode__(self):
        return self.CarID

Population code:

import os
os.environ.setdefault('DJANGO_SETTINGS_MODULE','TKTrading.settings')
import django
django.setup()
from APP.models import Category, ModelName, CarStorage

def populate():
    BASE_DIR = '/Users/apple/WebWorkshop/TKTrading/'
    DATA_DIR = os.path.join(BASE_DIR, 'APP/Data')    
    CATEGORY = open(os.path.join(DATA_DIR, 'CATEGORY.txt'),'r')
    global CategoryList
    CategoryList = []
    for line in CATEGORY:
        newC = Add_Category(line)
        CategoryList.append(newC)
    CATEGORY.close
    MODELNAME = open(os.path.join(DATA_DIR, 'Model.txt'), 'r')
    global ModelList
    ModelList = []
    for line2 in MODELNAME:
        newM = Add_ModelName(line2)
        ModelList.append(newM)
    MODELNAME.close
    CARSTORAGE = open(os.path.join(DATA_DIR, 'CARSTORAGE.txt'), 'r')
    for line3 in CARSTORAGE:
        print(line3)
        c = line3.split(',')
        ID = str(c[0])
        category = str(c[1])
        model = str(c[2])
        storage = int(c[3])
        year = int(c[4])
        Add_CarStorage(ID, category, model, storage, year)
    CARSTORAGE.close

def Add_Category(name):
    c = Category.objects.get_or_create(name = name)[0]
    c.save()
    return c

def Add_ModelName(name):
    m = ModelName.objects.get_or_create(name = name)[0]
    m.save()
    return m

def Add_CarStorage(ID, category, model, storage, year):
    for CATEGORY in CategoryList:
        if CATEGORY.name == category:
            category = CATEGORY
    for MODEL in ModelList:
        if MODEL.name == model:
            model = MODEL
    car = CarStorage.objects.get_or_create(CarID = ID,
                                           category = category,
                                           model = model,)[0]
    car.storage = storage
    car.perchasedYear = year
    car.save()
    return car

if __name__ =='__main__':
    print('Starting population...')
    populate()

For the population code, I have try two way but got the same message. One is put all the category and model in a list as object, the other one is using string to create new object directly.

In the end this is the whole message feedback:

Traceback (most recent call last):
  File "DBPopulation.py", line 77, in <module>
    populate()
  File "DBPopulation.py", line 45, in populate
    Add_CarStorage(ID, category, model, storage, year)
  File "DBPopulation.py", line 69, in Add_CarStorage
    model = model,)[0]
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 471, in get_or_create
    return self.get(**lookup), False
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 376, in get
    clone = self.filter(*args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 794, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 812, in _filter_or_exclude
    clone.query.add_q(Q(*args, **kwargs))
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1227, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1253, in _add_q
    allow_joins=allow_joins, split_subq=split_subq,
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1183, in build_filter
    condition = lookup_class(lhs, value)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/lookups.py", line 19, in __init__
    self.rhs = self.get_prep_lookup()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/fields/related_lookups.py", line 100, in get_prep_lookup
    self.rhs = target_field.get_prep_value(self.rhs)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 946, in get_prep_value
    return int(value)
ValueError: invalid literal for int() with base 10: 'Wing'

TXT file:

2512-305,Wing,Nissan UD,10,2003
2010-41,Wing,Hino,4,1997
2607-312,Cargo Drop Side,Isuzu,6,2012
2411-341,Cargo Drop Side,Nissan UD,7,2000
2406-326,Tractor,Nissan UD,12,1996
2211-101,Other,Komatsu,1,0

I understand there might have problems like putting string or nothing in the integer field, but I have reread many time and still not figure out.

Answer 1

The problem is with your Add_CarStorage function.

when

if MODEL.name == model:

is true you are replacing string model with MODEL which is a ModelName instance but when the condition is false you are not updating the variable model with anything. A quick fix would be to use get_or_create call only when the condition is true.