我正在从CSV中读取信息到我的django模型，但它不断抛出ValueError: Cannot assign "'Sheffield United'": "Match.home_team" must be a "Team" instance.我可以在管理界面中添加数据（可能很明显），但尝试以编程方式执行此操作会让我知道错误。
我和'联盟'有同样的问题，只是为了测试而评论 - 联盟（“E2”）对象和团队'谢菲尔德联队'存在于数据库中，因为我添加它们来测试。
然后我根据this answer.将其更改为home_team = Team.objects.get(id=row[2])。我认为这可能已经解决了最初的问题，但我现在得到：ValueError: invalid literal for int() with base 10: 'Sheffield United'，这是令人困惑的，因为它是一个字符串。
Models.py：
class League (models.Model):
name = models.CharField(max_length=2)
last_modified = models.CharField(max_length=50)
def __unicode__(self):
return unicode(self.name)
class Team(models.Model):
team_name = models.CharField(max_length=50)
league = models.ForeignKey(League)
team_colour = models.CharField(max_length=6, null=True, blank=True)
def __unicode__(self):
return unicode (self.team_name)
class Match(models.Model):
RESULT_CHOICES = (
('H', 'Home'),
('D', 'Draw'),
('A', 'Away'))
league = models.ForeignKey(League)
match_date = models.DateTimeField()
home_team = models.ForeignKey(Team)
away_team = models.CharField(max_length=50)
full_time_home_goals = models.PositiveSmallIntegerField(blank=True, null=True)
full_time_away_goals = models.PositiveSmallIntegerField(blank=True, null=True)
full_time_result = models.CharField(max_length=1, choices=RESULT_CHOICES, blank=True, null=True)
half_time_home_goals = models.PositiveSmallIntegerField(blank=True, null=True)
half_time_away_goals = models.PositiveSmallIntegerField(blank=True, null=True)
half_time_result = models.CharField(max_length=1, choices=RESULT_CHOICES,blank=True, null=True)
home_shots = models.PositiveSmallIntegerField(blank=True, null=True)
away_shots = models.PositiveSmallIntegerField(blank=True, null=True)
home_shots_on_target = models.PositiveSmallIntegerField(blank=True, null=True)
away_shots_on_target = models.PositiveSmallIntegerField(blank=True, null=True)
home_corners = models.PositiveSmallIntegerField(blank=True, null=True)
away_corners = models.PositiveSmallIntegerField(blank=True, null=True)
home_yellow = models.PositiveSmallIntegerField(blank=True, null=True)
away_yellow = models.PositiveSmallIntegerField(blank=True, null=True)
home_red = models.PositiveSmallIntegerField(blank=True, null=True)
away_red = models.PositiveSmallIntegerField(blank=True, null=True)
def __unicode__(self):
return unicode(self.home_team) + " v " + unicode(self.away_team) + " " + unicode(self.match_date)
class Meta:
verbose_name_plural = "Matches"
我正在使用的管理命令是:(现在我从命令行运行它来调试它，所以已经删除了BaseCommand子类化的代码 - 它没有影响我看到的错误。 ）
from django.core.management.base import BaseCommand, CommandError
import csv
import csvImporter
from core.models import Match
master_data = open ('/Users/chris/Dropbox/Django/gmblnew/data/testfile.csv', 'r')
data = list(tuple(rec) for rec in csv.reader(master_data, delimiter=','))
from core.models import Match, League
for row in data:
current_match = Match(
league=row[0],
match_date = row[1],
home_team = row[2],
away_team = row[3],
full_time_home_goals = row[4],
full_time_away_goals = row[5],
home_shots = row[10],
away_shots = row[11],
home_shots_on_target = row[12],
away_shots_on_target = row[13],
home_corners = row[16],
away_corners = row[17],
full_time_result = row[6],
)
print current_match
原始追溯（'必须是实例'错误：）
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 453, in execute_from_command_line
utility.execute()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 392, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 272, in fetch_command
klass = load_command_class(app_name, subcommand)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 77, in load_command_class
module = import_module('%s.management.commands.%s' % (app_name, name))
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module
__import__(name)
File "/Users/chris/Dropbox/Django/gmblnew/core/management/commands/ImportCSV.py", line 24, in <module>
full_time_result = row[6],
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/base.py", line 403, in __init__
setattr(self, field.name, rel_obj)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/fields/related.py", line 405, in __set__
self.field.name, self.field.rel.to._meta.object_name))
ValueError: Cannot assign "'Sheffield United'": "Match.home_team" must be a "Team" instance.
最近的追溯：
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 453, in execute_from_command_line
utility.execute()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 392, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 272, in fetch_command
klass = load_command_class(app_name, subcommand)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 77, in load_command_class
module = import_module('%s.management.commands.%s' % (app_name, name))
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module
__import__(name)
File "/Users/chris/Dropbox/Django/gmblnew/core/management/commands/ImportCSV.py", line 14, in <module>
home_team = Team.objects.get(id=row[2]),
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/manager.py", line 143, in get
return self.get_query_set().get(*args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 379, 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 655, 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 673, 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 1266, in add_q
can_reuse=used_aliases, force_having=force_having)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1197, in add_filter
connector)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/where.py", line 71, in add
value = obj.prepare(lookup_type, value)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/where.py", line 339, in prepare
return self.field.get_prep_lookup(lookup_type, value)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 322, in get_prep_lookup
return self.get_prep_value(value)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 555, in get_prep_value
return int(value)
ValueError: invalid literal for int() with base 10: 'Sheffield United'
目前，我正在阅读一些初始数据进行测试，但是将CSV操作到数据库中是我将要定期进行的操作，因此需要一些指导。 （我已经看了几个CSVImporter工具 - 现在，我不想使用它们，因为我想了解我正在做的事情，我觉得我写的应该是如果我能解决这个问题就足够了。）
答案 0 :(得分：3)
由于home_team是ForeignKey，因此它只能接受该模型的实例;你试图传递一个字符串，这是主队的名字，这就是这个错误的含义：
ValueError: Cannot assign "'Sheffield United'": "Match.home_team" must be a "Team" instance.
在导入器脚本中，您需要搜索代表主组的对象，并将其指定为外键。您可以使用get_or_create来获取现有团队，也可以为团队名称创建新团队;像这样：
from django.core.management.base import BaseCommand, CommandError
import csv
import csvImporter
from core.models import Match
master_data = open ('/Users/chris/Dropbox/Django/gmblnew/data/testfile.csv', 'r')
data = list(tuple(rec) for rec in csv.reader(master_data, delimiter=','))
from core.models import Match, League, Team
for row in data:
league, _ = League.objects.get_or_create(name=row[0])
home_team, _ = Team.objects.get_or_create(team_name=row[2], league=league)
away_team, _ = Team.objects.get_or_create(team_name=row[3], league=league)
current_match = Match(
league = league,
home_team = home_team,
away_team = away_team,
match_date = row[1],
full_time_home_goals = row[4],
full_time_away_goals = row[5],
home_shots = row[10],
away_shots = row[11],
home_shots_on_target = row[12],
away_shots_on_target = row[13],
home_corners = row[16],
away_corners = row[17],
full_time_result = row[6],
)
print current_match
这一行Team.objects.get_or_create(team_name=row[2])表示：
“尝试获取其team_name与其值相同的Team对象
row[2]，如果它不存在，则创建一个新的Team对象并将其返回 代替“
get_or_create将返回一个2元组，第二部分是一个布尔值，用于告诉您是创建了新项目还是检索了现有项目。由于我们只对第一部分感兴趣，因此我更新了代码以仅使用实例并忽略第二个值。
答案 1 :(得分：1)
试试home_team = Team.objects.get(team_name=row[2])。问题来自于Team.id字段是一个整数字段（因为没有定义primary_key字段，django会自动创建一个整数id字段）并且您要分配一个字符串它