差异两个数组的Python方式

Question

我调用两个API端点并收到以下响应：

applications = [{'id': '1', 'name': 'app1'}, {'id': '2', 'name': 'app2'}]
types = [{'id': '3', 'name': 'app1'}, {'id': '4', 'name': 'app1'}]

我正在寻找以下输出：

app1 has 2 types.
app2 has 0 types.

我可以使用嵌套的for循环来实现这一目标，但是实现这一目标的最Python方式是什么？

Answer 1

types = [app['name'] for app in types]
apps = {app['name']:types.count(app['name']) for app in applications}

应用程序字典将为您提供类型中的应用程序计数。 这是您要找的东西吗？

Answer 2

您也可以使用pandas完成此操作：

import pandas as pd
counts = pd.DataFrame(types).groupby('name').count()
application_names = {x['name'] for x in applications}
{name: counts['id'].get(name, 0) for name in application_names}

Answer 3

您可以使用collections.Counter来映射应用名称以有效地键入计数：

from collections import Counter
counts = Counter(type['name'] for type in types)
for app in applications:
    print(f'{app["name"]} has {counts[app["name"]]} types.')

输出：

app1 has 2 types.
app2 has 0 types.