Working with files in Python starts with deciding whether your program needs to read data or write it. File handling lets Python read from a named file or write data to it, and open() returns the file object used to…
A table can keep one row per record while storing each measurement in a separate column. Pandas melt turns selected measurement columns into labeled rows, and pivot reshapes those rows into columns again. This article walks through choosing columns for…
Some calculations start with a known number of values that need initial contents. Python provides ways to create that set, from a general-purpose list to a numerical array with a chosen type or shape. I’ll show how to choose among…
Related values often arrive in separate lists, such as names in one list and scores in another. Python’s zip() function pairs items at matching positions and returns an iterator that yields tuples. I’ll explain what zip() returns and show how…
A script that uses Python’s math module needs a way to refer to its code. An import statement makes a module or selected names available to your script. I’ll show how to choose an import form and check which locations…
An unfamiliar Python value can leave you unsure what operations it supports. type() reports the value’s class, which defines what its instances can do, or creates a class when called with three arguments. I’ll walk through both forms of type()…
To reuse a function across Python files, you can put it in one file and import that file where you need it. A Python module is a file of statements and definitions, usually with a .py extension, that another file…
When a script saves a file inside a new folder, that folder has to exist first. Python’s standard library provides pathlib for working with paths, and Path.mkdir() creates a folder while parents=True tells it to create any missing folders above…
Names and scores can be paired by position to make rows for a list of records. A Python list of tuples stores those rows in an outer list, with each tuple holding the ordered fields for one row. I’ll show…
Matching each name with its score means using the values at the same positions in both lists. Python’s zip() lets a loop process values from corresponding positions together. I’ll show how to choose a loop for the information each pass…