This is a very useful page for practicing regular expressions. It needs a lot of practice to be comfortable with these. I did some practice on Dataquest but that is just an introductory step.
I remembered some concepts on statistics like simple random, stratified and cluster sampling from Dataquest, which does a pretty good job on explaining these topics. We can also find information here
When we describe a sample or a population (by measuring averages, proportions, and other metrics; by visualizing properties of the data through graphs; etc.), we do descriptive statistics.
When we try to use a sample to draw conclusions about a population, we do inferential statistics (we infer information from the sample about the population).
Finally, I’ve explored the notebooks on wine dataset and it’s cool that I can now understand the basic coding in R and also in Python from the users! It’s easy to implement a machine learning algorithm in both languages, the difficult part is understand how it functions.
I must keep in mind that learning data science is not a matter of months, but a matter of years. Like in every field, someone has to commit to be an expert. There are so many things to learn and certainly we cannot excel at everything, but consistency is the key to make progress steadily. One brick each day and soon there will be a wall!
Angelo's progress in data analysis 