Python 如何在django中显示查询集的直方图 目标

通常，应用程序显示特定Twitter标签的位置数据。例如，如果用户输入“python”。该应用程序在Twitter上搜索包含标签“python”的最新推文，并在可能的情况下显示这些推文的位置数据

目前，位置数据显示为dict，这是通过Models.py中的

def display\u locations（self）

功能实现的

现在，我试图在柱状图上显示这些数据。我已经在下面的Views.py中编写了

draw\u histogram（）。我怀疑一个有效的解决方案可能是调用方法：
Hashtag.display\u locations
在函数中：
draw\u histogram（）
，但我不确定

我有两个备选问题：

在视图.py中的
绘制直方图（）
中，如何设置
国家/地区列表以实现目标

也许在
类SearchResultsView（generic.ListView）
中包含
draw\u histogram（）
函数作为一种方法更合适？如果是，我该如何做
错误
代码
型号.py

class Hashtag(models.Model):
    """ Model representing a specific Hashtag serch by user """
    search_text = models.CharField(max_length=140, primary_key=True)
    locations = models.ManyToManyField(Location, blank=True)

    def __str__(self):
        """ String for representing the Model object (search_text) """
        return self.search_text

    def display_locations(self):
        """ Creates a frequency dict of the locations attached to the Hashtag model """
        country_list = list(self.locations.values_list('country', flat=True).all())
        for country in country_list:
            location_freq = {i:country_list.count(i) for i in set(country_list)}
            return location_freq

class SearchResultsView(generic.ListView):
    """ Generic class-based view listing search results of locations """
    model = Hashtag
    template_name = 'mapping_twitter/results.html'

    def get_queryset(self, **kwargs):
        """ Restrict the results to the search_text entered on the Form """
        form_input = self.request.GET.get('search_text')
        qs = Hashtag.objects.all().filter(search_text__iexact=form_input)
        return qs

    def get_context_data(self, **kwargs):
        context = super(SearchResultsView, self).get_context_data(**kwargs)
        context['search_text', 'locations'] = self.get_queryset()
        return context


def draw_histogram(request, self):
    """ Function to display a histogram of locations associated with the Hashtag """
    country_list = list(self.locations.values_list('country', flat=True).all())
    for country in country_list:
        location_freq = {i:country_list.count(i) for i in set(country_list)}
    plt.bar(list(country_freq.keys()), country_freq.values(), color='g')
    # redirect into the BytesIO object
    f = io.BytesIO()
    plt.savefig(f, format="png", facecolor=(0.95,0.95,0.95))
    plt.clf()
    # Add the contents of the BytesIO object to the response and return
    return HttpResponse(f.getvalue(), content_type="image/png")

视图.py

class Hashtag(models.Model):
    """ Model representing a specific Hashtag serch by user """
    search_text = models.CharField(max_length=140, primary_key=True)
    locations = models.ManyToManyField(Location, blank=True)

    def __str__(self):
        """ String for representing the Model object (search_text) """
        return self.search_text

    def display_locations(self):
        """ Creates a frequency dict of the locations attached to the Hashtag model """
        country_list = list(self.locations.values_list('country', flat=True).all())
        for country in country_list:
            location_freq = {i:country_list.count(i) for i in set(country_list)}
            return location_freq

class SearchResultsView(generic.ListView):
    """ Generic class-based view listing search results of locations """
    model = Hashtag
    template_name = 'mapping_twitter/results.html'

    def get_queryset(self, **kwargs):
        """ Restrict the results to the search_text entered on the Form """
        form_input = self.request.GET.get('search_text')
        qs = Hashtag.objects.all().filter(search_text__iexact=form_input)
        return qs

    def get_context_data(self, **kwargs):
        context = super(SearchResultsView, self).get_context_data(**kwargs)
        context['search_text', 'locations'] = self.get_queryset()
        return context


def draw_histogram(request, self):
    """ Function to display a histogram of locations associated with the Hashtag """
    country_list = list(self.locations.values_list('country', flat=True).all())
    for country in country_list:
        location_freq = {i:country_list.count(i) for i in set(country_list)}
    plt.bar(list(country_freq.keys()), country_freq.values(), color='g')
    # redirect into the BytesIO object
    f = io.BytesIO()
    plt.savefig(f, format="png", facecolor=(0.95,0.95,0.95))
    plt.clf()
    # Add the contents of the BytesIO object to the response and return
    return HttpResponse(f.getvalue(), content_type="image/png")

draw_histogram（self，request）@HemanthSP，我按照建议尝试了以下错误：
TypeError:draw_histogram（）缺少一个必需的位置参数：'request'
是
draw_histogram（）
的一个实例方法，还是仅仅是一个全局函数？根据您的缩进，它是一个全局函数，但它返回一个
HttpResponse
对象。@Tsang YiShen，
draw\u histogram（）
是一个全局函数。我从这里复制了格式：。如果您知道使用
draw_histogram（）
作为
SearchResultsView
的实例方法来实现目标，那就好了！