在 Django/Python 中将 string 转换为 int 时遇到问题

Question

我正在尝试将字符串转换为 int，以便我可以保留运行总计，并希望能够在 django 模板中输出。

def stats(request):
    stats = []
    players = Player.objects.all()

    for player in players:
        player_stats = PlayerStat.objects.filter(player__id=player.pk)
        for n,stat in enumerate(player_stats):
            if n == 0: 
                    passing_completions = stat.passing_completions
            else:
                passing_completions += stat.passing_completions

        stats.append((player.first_name, player.last_name, player.team, passing_completions))

    return render_to_response('preps/stats.html', {'stats': stats, })

我尝试在 stat.passing_completions 周围添加 int() ，但随后只会抛出错误 invalid Literal for int() with base 10: ''。

然后我使用 isdigit() 方法来确保只有带有数字的字符串才尝试像这样转换：

for player in players:
    player_stats = PlayerStat.objects.filter(player__id=player.pk)

    for n,stat in enumerate(player_stats):
        if n == 0: 
            if stat.passing_completions.isdigit():
                passing_completions = int(stat.passing_completions)
        else:
            if stat.passing_completions.isdigit():
                passing_completions += int(stat.passing_completions)

    stats.append((player.first_name, player.last_name, player.team, passing_completions))

但随后我在渲染时收到 Caught TypeError 错误：'int' object不是可迭代的

模型结构

class PlayerStat(models.Model):
    player = models.ForeignKey(Player)

    week_num = models.CharField(
        max_length = 10,
        choices = (('1', 'Sep 2nd',), ('2', 'Sep 9th',), ('3', 'Sep 16th',),('4', 'Sep 23rd',), ('5', 'Sep 30th',), ('6', 'Nov 2nd',),('7', 'Nov 7th',), ('8', 'Nov 14th',), ('9', 'Nov 21st',),('10', 'Nov 28th',), ('11', 'Dec 4th',), ('12', 'Dec 11th',), ),
        blank = True,
        null=True
        )
    rushing_attempts = models.CharField(
        max_length = 100,
        verbose_name = "Rushing Attempts",
        blank=True
        )
    rushing_yards = models.CharField(
        max_length = 100,
        verbose_name = "Rushing Yards",
        blank=True
        )
    rushing_touchdowns = models.CharField(
        max_length = 100,
        verbose_name = "Rushing Touchdowns",
        blank=True
        )
    passing_completions = models.CharField(
        max_length = 100,
        verbose_name = "Passing Completions",
        blank=True
        )
    passing_attempts = models.CharField(
        max_length = 100,
        verbose_name = "Passing Attempts",
        blank=True
        )
    passing_yards = models.CharField(
        max_length = 100,
        verbose_name = "Passing Yards",
        blank=True
        )
    passing_touchdowns = models.CharField(
        max_length = 100,
        verbose_name = "Passing Touchdowns",
        blank=True
        )
    receptions = models.CharField(
        max_length = 100,
        verbose_name = "Receptions",
        blank=True
        )
    receiving_yards = models.CharField(
        max_length = 100,
        verbose_name = "Receiving Yards",
        blank=True
        )
    receiving_touchdowns = models.CharField(
        max_length = 100,
        verbose_name = "Receiving Touchdowns",
        blank=True
        )

任何帮助将不胜感激。

谢谢

Answer 1

我有时会使用这个愚蠢的技巧：

 a = int('0' + someString)

在字符串前面添加一个零可以保证字符串中至少有“0”。
现在，可以肯定的是，您可以使用正则表达式从“'0'+someString”中提取所有数字。

Answer 2

我知道这是一个老问题，但如果有人需要，这里有一个我用来毫无问题地将字符串转换为 int 的小解决方案：

def int_or_0(value):
    try:
        return int(value)
    except:
        return 0

就是这样。 ;)

Answer 3

您应该检查 stat.passing_completions 是否不是空字符串。你可以使用：

for player in players:
    player_stats = PlayerStat.objects.filter(player__id=player.pk)
    for n,stat in enumerate(player_stats):
        if n == 0 and stat.passing_completions:  # n is 0 and passing_completions is something meaningful
                passing_completions = int(stat.passing_completions)
        elif stat_passing_completions:  # n is not 0
            passing_completions += int(stat.passing_completions)
        else:
            pass  # in this case, stat.passing_completions is an empty string ('')

    stats.append((player.first_name, player.last_name, player.team, passing_completions))