How to Serialize a Python Dict into a String and Back?

Problem Formulation Given a Python dictionary containing lists and other data structures. You want to store the dictionary in a file or send it over the network in a more efficient form. How to serialize a Python dictionary into a string, and then deserialize the string back to a dictionary data structure? Here’s a rough … Read more

How to End a Function Def in Python?

Problem Formulation Given a function definition in Python, starting with the keyword def: How to know when a “def” of a function ends? For example, in Java and C++, functions are enclosed with opening and closing parentheses {…}, so the ending of a function is not ambiguous. Ending a Function Syntactically In Python, whitespace indentation … Read more

How to Rename Column Names in Pandas?

Problem Formulation Given a Pandas DataFrame with column labels, and a list of new column names as strings. How to change the column names to replace the original ones? Here’s an example using the following DataFrame: You want to rename the column names [‘Col_A’, ‘Col_B’, ‘Col_C’] to [‘a’, ‘b’, ‘c’] so that the resulting DataFrame … Read more

NumPy Boolean Indexing

You can index specific values from a NumPy array using another NumPy array of Boolean values on one axis to specify the indices you want to access. For example, to access the second and third values of array a = np.array([4, 6, 8]), you can use the expression a[np.array([False, True, True])] using the Boolean array … Read more

What’s the Best NumPy Book?

Fear of missing out in data science? Data science and machine learning are taking over. Data-driven decision making penetrates every single company nowadays. Data science is indeed the “sexiest job in the 21st century“! There is one Python library which is the basis of any data science related computation you can undertake as a Python … Read more

How to Get a Windows Screenshot in Python?

Problem Formulation Say, you run a Python program on your Windows machine and you want it to take a screenshot. How to accomplish this programmatically? Method 1: Multiple Screen Shots Module To programmatically record one or more screenshots in your Python program, run the sct.shot() function from the mss module. Install the Multiple Screen Shots … Read more