Question

我有一个Django项目，我的模型，视图和URL已设置完毕。路径结构如下：

--mainProject
--measurements
    --views.py
    --urls.py
    --models.py
    --migrations
    --templates.py
    --management
        --commands
            --add_data.py
            --clear_data.py
            --init.py
            --_pycache_

构建此项目时，我首先创建了models.py，然后进行了迁移。之后，我迁移了。 add_data.py文件将数据添加到表中，clear_data.py文件删除数据。我运行了add_data.py文件并且它运行了一次，但是我遇到了类似的错误。我忘记了如何通过命令行运行它。但是，现在如果我删除数据库并尝试运行add_data.py文件，我会收到此错误：

来自measurements.models导入区域，类别，位置，测量 ModuleNotFoundError：没有名为'measurements'的模块

这是我的代码：

models.py

from django.db import models
from django.db.models import Avg

class Area(models.Model):
    id = models.IntegerField(primary_key=True)
    name = models.CharField(max_length=200)
    longitude = models.FloatField()
    latitude = models.FloatField()

    def number_of_locations(self):
        return len(self.location_set.all())

    # Function to get the average measurements of locations in area
    def average_measurement(self):
        return Measurement.objects.filter(location__area=self).aggregate(Avg('value'))['value__avg']

    # Get all category names for area
    def category_names(self):

            categories = self.category_set.all()
            cList = ""

            for category in categories:
                cList+= category.name + ", "

            return cList[:-2]

    def __str__(self):
        return self.name

class Location(models.Model):
    id = models.IntegerField(primary_key=True)
    name = models.CharField(max_length=200)
    altitude = models.IntegerField(verbose_name="Altitude in feet")
    area = models.ForeignKey(Area, on_delete=models.CASCADE)

    def __str__(self):
        return self.area.name + ":" + self.name

class Measurement(models.Model):
    id = models.IntegerField(primary_key=True)
    value = models.FloatField()
    date = models.DateTimeField()
    location = models.ForeignKey(Location, on_delete=models.CASCADE)

    def __str__(self):
        return "measurement@" + self.location.__str__()


class Category(models.Model):
    id = models.IntegerField(primary_key=True)
    name = models.CharField(max_length=140)
    description = models.CharField(max_length=250)
    members = models.ManyToManyField(Area)

    def __str__(self):
        return self.name

add_data.py

from measurements.models import Area, Category, Location, Measurement
import random
from django.core.management.base import BaseCommand
from django.utils import timezone


class Command(BaseCommand):
    help = "adds sample entities to the application"

    def handle(self, *args, **options):

        area_data = [
            [1, "Grand Canyon", 20, 30],
            [2, "Boca Raton", 40, 50],
            [3, "Atlanta", 60, 70],
            [4, "Mount Hood", 80, 90],
            [5, "Mount Rainer", 46.5, 121.5],
            [6, "Saint Olaf", 44, 93],
            [7, "Mount St. Helens", 46, 122]
        ]

        for ad in area_data:
            a = Area(name=ad[1], id=ad[0], longitude=ad[2], latitude=ad[3])
            a.save()

        location_data = [
            [11, "South rim", 200, 1],
            [12, "North rim", 300, 1],
            [13, "Phantom Ranch", 100, 1],
            [14, "Waterfront", 10, 2],
            [15, "Town center", 15, 2],
            [16, "Town center", 310, 3],
            [17, "University", 320, 3],
            [18, "Mall", 330, 3],
            [19, "Airport", 350, 3],
            [20, "South pass", 3500, 4],
            [21, "North rim", 4500, 4],
            [22, "Crater", 4000, 4],
            [23, "North pass", 14000, 5],
            [24, "South glacier", 15000, 5],
            [25, "Ranger station", 16000, 5],
            [26, "Summit", 17000, 5],
            [27, "Yttrboe", 250, 6],
            [28, "Science", 250, 6],
        ]

        no_measurements_location_ids = [23]

        for locd in location_data:
            loc = Location(id=locd[0], name=locd[1], altitude=locd[2])
            a = Area.objects.get(pk=locd[3])
            loc.area = a
            loc.save()

        category_data = [
            [31, "Volcanos", "Areas that are on volcanoes", [4, 5]],
            [32, "East", "Areas that are in the east", [2, 3]],
            [33, "West", "Areas that are in the west", [1, 4, 5]],
            [34, "Wetlands", "Areas that are wetlands", []]
            ]

        for catd in category_data:
            cat = Category(id=catd[0], name=catd[1], description=catd[2])
            cat.save()
            for memb_id in catd[3]:
                a = Area.objects.get(pk=memb_id)
                cat.members.add(a)
            cat.save()

        num_meas_per_loc = 10

        for locd in location_data:
            loc_id = locd[0]
            if loc_id not in no_measurements_location_ids:
                loc = Location.objects.get(pk=loc_id)
                for meas_id in range(loc_id*100, loc_id*100+num_meas_per_loc):
                    val = random.uniform(5+loc_id*3, 15+loc_id*3)
                    meas = Measurement(value=val, id=meas_id, date=timezone.now())
                    meas.location = loc
                    meas.save()

我做错了什么导致了这个错误？

Answer 1

add_data.py是一个管理命令，而不是一个独立的脚本，所以你应该运行它：

python manage.py add_data

如果直接运行add_data.py，那么您的主项目目录（包含manage.py的目录）将不会自动进入Python路径，因此您将收到导入错误。

ModuleNotFoundError但模块的路径是正确的

1 个答案: