freeCodeCamp/curriculum/challenges/chinese/08-data-analysis-with-python/data-analysis-with-python-course/pandas-creating-columns.md

id, title, challengeType, videoId, bilibiliIds, dashedName

id	title	challengeType	videoId	bilibiliIds	dashedName
5e9a093a74c4063ca6f7c15c	Pandas 创建列	11	_sSo2XZoB3E	aid bvid cid 975568901 BV1b44y1b7Cg 409018052	pandas-creating-columns

--description--

在视频中我们使用的编辑器工具是在 notebook.ai 这个平台，你也可以选择用其他的平台，比如说 Google Colab 也是一个不错的选择。

以下有更多的资料：

• 在 GitHub 平台的 Notebooks
• 如何使用 Google Colab 来打开 GitHub 上的 Notebooks

--question--

--text--

哪段代码可以向 DataFrame certificates_earned 中添加一个 “Certificates per month” 列，就像下面所展示的？

      Certificates  Time (in months)  Certificates per month
Tom               8                16                    0.50
Kris              2                 5                    0.40
Ahmad             5                 9                    0.56
Beau              6                12                    0.50

--answers--

certificates_earned['Certificates'] /
certificates_earned['Time (in months)']

---

certificates_earned['Certificates per month'] = round(
    certificates_earned['Certificates'] /
    certificates_earned['Time (in months)']
)

---

certificates_earned['Certificates per month'] = round(
    certificates_earned['Certificates'] /
    certificates_earned['Time (in months)'], 2
)

--video-solution--

3