You can think of Data Visualization with Python as a sub-branch of Introduction to Data Analysis.
Data Visualization with Python really focuses on advancing your data visualization skills, whereas Introduction to Data Analysis introduces you to a comprehensive overview of data science.
Python is taught more in-depth in the Data Visualization Intensive than in Introduction to Data Analysis. Data Visualization with Python teaches Python syntax, functions, and lists, whereas Introduction to Data Analysis teaches just Python syntax. Data Visualization also includes an introduction to Seaborn, an advanced graphing library.
The Intensives do have some content overlap like Matplotlib, a data visualization library, and Pandas, a Python library where you'll learn to load, inspect and modify data – both of which are necessary to learn as you aggregate data, make an informed analysis of the data, and present the data.
Another thing to consider is the time commitment. Data Visualization with Python is 6 weeks long and Introduction to Data Analysis is 12 week.