Python：在以特定单词开头和结尾的DataFrame字符串对象中获取数字

Question

我希望字符串数字为整数，表示出现在 total 和 USD 之间的总成本。

示例数据框：

    id   name    lastname   message 
0   1   John    Doe        John have 100 USD, so he buy 5 eggs which total cost 10 USD
1   2   Mar     Aye        Mar have 10 USD, he just buy a banana from another shop for 16 USD

所以最终的结果应该是：

    id   name    lastname   message                                                             total
0   1   John    Doe        John have 100 USD, so he buy 5 eggs which total cost 10 USD         10
1   2   Mar     Aye        Mar have 10 USD, he just buy a banana from another shop for 16 USD  0

Answer 1

您可以使用正则表达式来捕获出现在“total”和“USD”之间的任何数字。

下面的代码将捕获任何数字（如果是多个数字，则需要进行一些调整，如果应该接受浮点数，但由于类型应该是 int，所以应该不需要）并将其转换为 int 类型。

df['total'] = df['message'].str.extract('total.*?(\d+).*?USD').fillna(0).astype(int)

结果：

id   name    lastname   message                                                             total
0   1   John    Doe        John have 100 USD, so he buy 5 eggs which total cost 10 USD         10
1   2   Mar     Aye        Mar have 10 USD, he just buy a banana from another shop for 16 USD  0