Update README.md (#266)

Author: Souvikns

README.md

@@ -39,6 +39,9 @@ For a good visualisation of the different data structures and algorithms, refer
 - https://visualgo.net/
 - https://www.cs.usfca.edu/~galles/visualization/
 
+You can use the examples given in the following book as tests for your code:
+- [https://opendatastructures.org/ods-python.pdf](https://opendatastructures.org/ods-python.pdf)
+
 Why we use Python?
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