When dividing numbers in Python, / and // can give different results. The / operator returns the quotient, while // rounds it down to the greatest whole number no greater than the quotient. A Python example compares their results and…
Updating Python code that uses xrange() starts with knowing which Python version the code targets. In Python 2, xrange() provides an immutable integer sequence for loops, while Python 3 uses range() for that job. This article explains what xrange() did…
To convert an integer into a binary string, you need a way to express its value with the digits zero and one. Python can return that string with a 0b prefix or as binary digits without the prefix. I’ll compare…
To save Python print() output in a file, send it to an open text file instead of the terminal. The file argument lets print() write its text to that file. This article shows how to write print() output to a…
When you want one Python file to use a function or class from another, you can import its definitions instead of copying them. A Python module is a file whose names can be made available to other code with an…
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 file that already contains notes can be a place to add another line without losing what’s there. Python’s append mode writes new text at the end, while other modes can create or replace a file. I’ll explain how the…
A class may need to show a value that changes with its other data, and callers may still read it with dot notation. Python’s property decorator lets a class expose a method as an attribute that can compute a value…
When a list of records includes entries that pass a condition and entries that do not, selecting the matches calls for a test. Python’s filter() applies a test, called a predicate, to each item and returns an iterator containing the…
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()…