Add intro video

1-Introduction/01-defining-data-science/README.md

@@ -1,5 +1,6 @@
 # Defining Data Science
 
+[![Defining Data Science Video](images/video-def-ds.png)](https://youtu.be/pqqsm5reGvs)
 ## Pre-Lecture Quiz
 
 [Pre-lecture quiz]()
@@ -146,8 +147,6 @@ In this challenge, we will try to find concepts relevant to the field of Data Sc
 
 [Post-lecture quiz]()
 
-## Review & Self Study
-
 ## Assignment
 
-[Assignment Title](assignment.md)
+[Think About Data Science Scenarios](assignment.md)

2-Working-With-Data/07-python/README.md

@@ -1,5 +1,7 @@
 # Working with Data: Python and the Pandas Library
 
+[![Intro Video](images/video-ds-python.png)](https://youtu.be/dZjWOGbsN4Y)
+
 While databases offer very efficient ways to store data and query them using query languages, the most flexible way of data processing is writing your own program to manipulate data. While in many cases doing database query will be more effective way, in some cases you might need some more complex data processing, which cannot be easily done using SQL.
 
 Data processing can be programmed in any programming language, but there are certain languages that are higher level with respect to working with data. Data scientists typically prefer one of the following languages: