A dictionary is a Python collection that stores data as key-value pairs. Instead of asking for "the item at position 3," you ask for "the value stored under the key 'voltage'." You create dictionaries with curly braces, access values by key, and add, update, or remove entries as your program runs. Because keys are looked up directly rather than by scanning through positions, dictionaries give fast access even when they hold large amounts of data.
This matters in EGN3214 because most engineering data is labeled, not just ordered. Sensor readings tied to sensor IDs, material properties tied to material names, unit conversion factors tied to unit symbols, and student records tied to ID numbers all map naturally onto key-value pairs. Learning dictionaries also sharpens your ability to choose among lists, tuples, dictionaries, and sets, which is one of the central skills of this module.
As you watch, pay attention to four things: the syntax for creating a dictionary and retrieving a value by key, what happens when you assign to a key that does or does not already exist, the methods keys(), values(), and items() and how they drive loops over a dictionary, and the rules about what can serve as a key. Try each example in your own Python environment and deliberately trigger a KeyError so you recognize it later.
A full tutorial lesson on Python dictionaries from a long-running beginner Python series. Based on its length and placement in the course, it likely walks through creating dictionaries with curly braces, accessing and changing values by key, adding and deleting entries, and the common built-in dictionary methods, with typed code examples throughout.
At about ten minutes it is the most complete single treatment of the topic here, covering creation, access, and modification in one pass, and CodeWithHarry's day-by-day Python series is a well-established beginner resource.
A short, focused introduction from Khan Academy's Intro to CS - Python course. The description indicates it defines a new dictionary using curly brackets and shows how to access a value by its key, framing dictionaries as a way to store data in key-value pairs.
It is the cleanest starting point if dictionaries are new to you, and Khan Academy's careful, slow-paced explanations make it a reliable first look at the Creating and Accessing Dictionaries subtopic.
A lecture from the IIT Madras BS Degree Programme course Programming in Python that goes beyond the basics to cover keys, values, and the essential dictionary methods. Expect attention to keys(), values(), and related methods, which are exactly the tools you use to loop over a dictionary's entries.
It extends the introductory videos into the Modifying and Iterating Over Dictionaries subtopics, and it comes from a structured university course sequence, so the terminology matches what you will see in formal coursework.
Together these three videos build the dictionary half of MO4 and MO5: Khan Academy establishes what a key-value pair is and how access by key differs from access by position, CodeWithHarry extends that into creating, modifying, and deleting entries with full code examples, and the IIT Madras lecture supplies the keys(), values(), and items() methods you need to iterate over dictionary contents. The iteration material also reinforces MO2, since looping over a dictionary's keys or items is a direct application of for loops to a non-numeric sequence. Once you can describe a dictionary's mutability, its access-by-key behavior, and its lookup speed, you have the basis for comparing it against lists, tuples, and sets and for justifying your choice of data structure in an engineering problem.
These videos were chosen from YouTube on October 2, 2026. Each has captions; the player turns them on. Videos on YouTube can be changed or removed — if one no longer plays, tell your instructor. If a player does not appear, use its Watch on YouTube link.