Search for tag: "accumulator"

Lesson 26.5 While-Loops vs For-Loops

We can always replace for-loops with while-loops, but should we? In this video we talk about the trade-offs of the two control structures and why it might be better to use over the other.

From  Hannah Lee on November 12th, 2020 29 plays

Lesson 26.3 While-Loop Ranges

While-loops require additional patterns beyond the simple accumulator pattern that we used in for-loops. In this video, we talk about the first such pattern, which is replacing the range iterator.…

From  Hannah Lee on November 12th, 2020 31 plays

Lesson 26.2 While-Loop Traces

While-loops can do everything that a for-loop can (and more) but they are much harder to use. That is why, in this video, we talk about how to debug a while-loop before we talk about how to write…

From  Hannah Lee on November 12th, 2020 31 plays

Zoom Oct. 27. Nested Lists and Dictionaries

This presentation explores the last built-in (as opposed to user-defined) types in this course. These types are often used to store data in files.We actually had an (accidental) sneak peak at these…

From  Hannah Lee on October 27th, 2020 7 plays

Lesson 19.6 Immutable Dictionary Functions

Since we can loop over dictionaries, that means we probably want to use them in functions with accumulators. In this video we show how to do this and why they are not that much different from lists.

From  Hannah Lee on October 27th, 2020 27 plays

Lesson 18.5 Immutable Table Functions

In this video we show how to write an immutable function on a table of data. In most ways this is no different than writing an immutable function on a list. Except that this time we may need multiple…

From  Hannah Lee on October 27th, 2020 25 plays

Zoom Oct. 15. For-Loops

In this session, we review the for-loop, which is the next control structure. This is the last control structure we will need for a while.For-loops are pretty easy to use in Python, and most students…

From  Hannah Lee on October 19th, 2020 6 plays

Lesson 17.6 Divide and Conquer Visualization

Just because you know how to write a divide-and-conquer algorithm does not mean you understand it. In this video we try to improve our understanding by visualizing divide-and-conquer. When we do this…

From  Hannah Lee on October 19th, 2020 41 plays

Lesson 16.8 Tuple Expansion (OPTIONAL)

This video introduces an advanced topic that is completely optional and will not appear on any exam. You might have noticed that some functions, like max can take an arbitrary number of arguments. In…

From  Hannah Lee on October 19th, 2020 8 plays

Lesson 16.6 Mutable For-Loops

Lists are mutables and support mutable functions. Many of these mutable functions contain for-loops. As we show in this video, this changes how we write the for-loop. In particular, we will not use…

From  Hannah Lee on October 19th, 2020 23 plays

Lesson 16.5 Positional For-Loops

Sometimes we need to perform a calculation on a string, list, or tuple, but we do not want to loop over this value. Instead, we want to loop over the positions of the value. In this video we show why…

From  Hannah Lee on October 19th, 2020 27 plays

Lesson 16.4 Range-Based For-Loops

Strings, lists, and tuples are not the only iterable types. In this video we introduce the range function, which creates another iterable value. This is going to allow us to do several things that we…

From  Hannah Lee on October 19th, 2020 30 plays

Lesson 16.3 Accumulators

One of the techniques that we say in the previous video was the accumulator variable. In this video we show that this is a general technique used in a fruitful function that requires a for-loop.

From  Hannah Lee on October 19th, 2020 27 plays

Lesson 16.2 For-Loop Design

In this video we show how to use for-loops in function definitions. In particular, we show that we go from a specification to code that uses a for-loop.

From  Hannah Lee on October 19th, 2020 28 plays