python - 如何仅格式化循环python中的项目数

Question

我在线读取了一个文件并将其转换为 JSON。我得到了结果，但想要格式化数字(23456876 到 23,456,875 和 345653 到 345,653 )

data_file = [{"name":"python", "downloads":23456876, "version": "3.4.2", "version_downloads": 345653 }]

我编写了代码来获取值，但是如果我在 for k in key 中使用 try except 语句。它不会转换，我也使用了另一种方式但是得到了 cannot convert automatic fields to mamual formatting or something

titles = ["name", "downloads", "version", "Latest downloads"]
key = ["name", "downloads", "version", "version_downloads"]

i = 0
while i < len(data_file):
    results = []
    for k in key: 
        print("{}: {}".format(titles[key.index(k)], data_file[i][k]))
    print()
    i+=1

现在的结果是这样的:

name: python
downloads: 23456876
latest version: 3.4.2
Latest downloads: 345653

我怎样才能将 downloads 打印为:

downloads: 2,345,676
Latest downloads: 345653

Answer 1

不确定你在做什么索引，但你可以使用 isinstance 检查整数并进行格式化，如果它是:

data_file = [{"name":"python", "downloads":23456876, "version": "3.4.2", "version_downloads": 345653 }]


titles = ["name", "downloads", "version", "Latest downloads"]
key = ["name", "downloads", "version", "version_downloads"]

for  d in data_file:
    for k in key:
        val = d[k]
        if isinstance(val, int):
            val = "{:,}".format(val)
        print("{}: {}".format(titles[key.index(k)], val))

输出:

name: python
downloads: 23,456,876
version: 3.4.2
Latest downloads: 345,653

我会使用字典来映射名称并进行查找，而不是索引:

titles = ["name", "downloads", "version", "Latest downloads"]
key = ["name", "downloads", "version", "version_downloads"]
match = dict(zip(key,titles))
for  d in data_file:
    for k in key:
        val = d[k]
        if isinstance(val, int):
            val = "{:,}".format(val)
        print("{}: {}".format(match[k], val))

输出:

name: python
downloads: 23,456,876
version: 3.4.2
Latest downloads: 345,653

如果唯一的区别是 "version_downloads"，那么使用 if 检查可能会更简单。