I kept typing 7 // 3 and expecting 3. I had just switched from a language where integer division truncates toward zero, so floor division felt like a bug until I ran the numbers. Once I traced the three ceiling…
Python stops on the line the moment it meets && inside an if statement, and the caret lands under the second ampersand. Every C-family language accepts those two characters for logical conjunction, so a parser error reads like a bug…
Print the result of the Python map function and you get an address instead of a list, because nothing has run yet. The four numbers you passed in are still waiting inside an iterator, and the values only appear when…
I keep coming back to the Python sum() function whenever I need a quick way to add up numbers. It is one of those built-in tools that seems simple on the surface but has enough quirks to trip you up…
I ran into a situation last year where I had a pandas DataFrame with 50 columns and needed to pull out specific columns by their numerical position. The column names were generated programmatically and I had no way to know…
I’ve parsed more text files than I can count over the years – logs, configs, CSV exports, API responses saved to disk. The job is always the same: open the file, read the content, turn raw text into something my…
I have been working with text data for years, and I keep coming back to the same tool whenever I need to find or transform strings in Python. That tool is the re module. It is one of those things…
## TLDR <!– wp:list –> <ul class=”wp-block-list”><!– wp:list-item –> <li>pow(a, n) raises a to the power n – same as a ** n</li> <!– /wp:list-item –> <!– wp:list-item –> <li>pow(a, n, b) adds modular exponentiation: (a ** n) % b…
Python frozenset() is an immutable version of the built-in set. Once created, a frozenset cannot be modified — elements cannot be added or removed. This immutability makes frozenset hashable, which means it can be used as a dictionary key, stored…
Python’s print() function defaults to writing to the console, but it also accepts a file keyword argument that redirects output to any writable file object. This works with any object that has a .write() method — files, io.StringIO, and similar…
