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

---
id: 5e9a093a74c4063ca6f7c15c
challengeType: 11
videoId: _sSo2XZoB3E
dashedName: pandas-creating-columns
---

# --description--

More resources:

\- [Notebook](https://notebooks.ai/rmotr-curriculum/freecodecamp-intro-to-pandas-902ae59b)

# --question--

## --text--

What code would add a "Certificates per month" column to the `certificates_earned` DataFrame like the one below?

```
      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--

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

---

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

---

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

## --video-solution--

3