Question

我正在尝试编写一段代码来查看文本条目是否包含50个或更多字符，如果是，则只显示50加省略号（...），否则它是否小于50然后只显示没有省略号的整个条目。

我目前的代码是：

from django.db import models

# Create your models here.

class Topic(models.Model):
    """A topic the user is learning about"""
    text = models.CharField(max_length=200)
    date_added = models.DateTimeField(auto_now_add=True)
    def __str__(self):
        """Return a string representation of the model"""
        return self.text

class Entry(models.Model):
    """Something specific learned about a topic"""
    topic = models.ForeignKey(Topic)
    text = models.TextField()
    date_added = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name_plural = 'entries'

    def __str__(self):
        if text.len() >= 50:
            """Return a string represerntation of the model"""
            return self.text[:50] + "..."
        else:
            return self.text

当我使用Python和Django运行时，我不断收到错误。我将如何解决此问题

Answer 1

使用：

<GridScreen>:
    label: label #referencing the label
    rows: 2
    Button:
        text: 'this button \n is the root'
        color: .8, .9, 0, 1
        font_size: 32
        on_press: root.btnpress() #calling the method 

    Label:
        id: label
        text: 'This is a label'
        color: .9, 0, .5, .5

而不是：

if len(self.text) >= 50:

Answer 2

from django.db import models

# Create your models here.

class Topic(models.Model):
    """A topic the user is learning about"""
    text = models.CharField(max_length=200)
    date_added = models.DateTimeField(auto_now_add=True)
    def __str__(self):
        """Return a string representation of the model"""
        return self.text

class Entry(models.Model):
    """Something specific learned about a topic"""
    topic = models.ForeignKey(Topic)
    text = models.TextField()
    date_added = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name_plural = 'entries'

    def __str__(self):
        if len(self.text) >= 50:
            """Return a string represerntation of the model"""
            return self.text[:50] + "..."
        else:
            return self.text

如何为字符长度创建if else语句

2 个答案: