Want to learn Python? Check out all the Python tutorials on PythonGuides.com. All these tutorials are written by Python experts with practical and real examples. Talk with our experts if you still have questions.
Four brackets, four behaviors. The list vs tuple vs set vs dictionary in Python choice comes down to three questions: can it change, does it keep order, and does it allow duplicates? A list is changeable and ordered, and a tuple is fixed. A set keeps unique items only, while a dictionary maps keys to … Read more >>
![Difference Between {} and [] Python](https://pythonguides.com/wp-content/uploads/2025/01/Difference-Between-and-Python.webp "Difference Between and Python")
When I build a small reporting script, I often need two very different things: a sequence of report rows and a quick way to look up details by an ID. Python uses [] for one of those jobs and {} for the other, so choosing the wrong brackets can cause confusing errors later. The difference between {} and [] in Python looks small … Read more >>
When I troubleshoot a reporting script, I often need to temporarily turn off a few lines without deleting them. Maybe an email notification sends too early, a file-writing step needs testing, or I want to isolate a function that causes an error. To comment out a block of code in Python, add a # at … Read more >>
Use is None. The difference between is None vs == None in Python is that is checks whether a name points to the one and only None object, while == asks the object’s __eq__ method, which a class can rewrite to say anything: I ran these snippets on Python 3.12.5, NumPy 2.5.3 and pandas 3.0.6; … Read more >>
A small reporting script often starts with simple labels such as customer names, status messages, and file paths. Then someone adds a name like O’Connor or a message with double quotes, and Python suddenly throws a syntax error. I have hit this problem many times while building automation scripts that read CSV files, create reports, … Read more >>
When I build small reporting scripts, I often start with a Python list. It is easy to collect daily sales, API response times, or file sizes in a list while the script runs. But once I need type-safe numeric storage or fast calculations, I convert that list into an array. The word “array” means different … Read more >>
Last month I was helping a small logistics company in Austin track quarterly bonuses for their 10-person warehouse team. Everything lived in a dictionary, employee names as keys, bonus amounts as values, because that’s the fastest way to store key-value pairs in Python. The problem showed up when their finance lead asked me to export that … Read more >>
To read a binary file into a byte array in Python, use bytearray(Path(“file.bin”).read_bytes()), or open the file in “rb” mode and wrap f.read() in bytearray(). read() gives you immutable bytes; bytearray is the mutable version you can change and write back. This guide also covers reading byte by byte, reading large files in chunks, readinto(), … Read more >>
I built a simple leave request app for a small U.S. team after our HR person kept tracking time off in a messy Excel sheet. I wanted a local Python tool that ten employees across Dallas, Chicago, and Seattle could use from the command line, with approved requests saved permanently in SQLite. Along the way, … Read more >>
I still remember the week I stopped tracking leave in a shared Excel file. I once helped a 10-person U.S. team whose HR tracker kept breaking, since someone overwrote someone else’s row or forgot to update a formula every month. So I built a tiny Python command-line app to log leave requests, backed by a … Read more >>