Remove some examples (#361)

Author: gahjelle

pandas-iterate-over-rows/README.md

@@ -2,10 +2,10 @@
 
 In these supplementary materials, you'll find the examples discussed in the Real Python tutorial [How to Iterate Over Rows in pandas, and Why You Shouldn't](https://realpython.com/pandas-iterate-over-rows/), along with some bonus materials.
 
-In addition to the third-party packages used in the tutorial, you should also install [perfplot](https://github.com/nschloe/perfplot) to play with the bonus examples. To install all dependencies into your virtual environment, you can run the following command:
+To install all dependencies into your virtual environment, you can run the following command:
 
 ```console
-$ python -m pip install pandas httpx codetiming perfplot
+$ python -m pip install pandas httpx codetiming
 ```
 
 You'll also find some additional code samples along the way, showing alternatives to looping, such as using list comprehensions. You'll also learn about alternative ways of looping.