MOD2: H6 - H9

Question 1

What if you try to use a Negative Number as an Index? Shouldn’t Python throw an Error?

Answer 1

Not as long as the Number’s an Integer.

If you give Python a Negative Number, it will start at the last item in the list and count backwards.

Question 2

For Sorting - What if a List has both strings and numbers in it?

Answer 2

Python sorts the numbers, then the strings.

Question 3

How would you count how many times an item is in a list?

Answer 3

count()

Question 4

How do you add a new item to a list?

Answer 4

append() or insert()

Question 5

What is the difference between reverse() and sort()?

Answer 5

sort() - will sort in alphabetical or numerical order.

reverse() - takes a list in the order it was created in, and reverses the order.

Question 6

How would you get a list of names to be sorted in reverse alphabetical order?

Answer 6

First - Sort it Alphabetically. sort()

Then - Reverse Sort it. reverse()

Question 7

What if I want a Range that’s printed in descending order?

Answer 7

Start with the Highest Number, end with a number that’s 1 less from where you want to stop, and give it a Step of -1.

Question 8

What happens if I change a list while I”m looping through it?

Answer 8

In Python, if you change a list while looping through it, the Loop will work with the change you made.

Question 9

What is the difference between a FOR Loop and a WHILE Loop?

Answer 9

For Loops run through a List of items.

While Loops keep running until the expression is True.

Question 10

How would you get a range of even numbers, from 1 to 100?

Answer 10

You would need to use a range function.

range(2, 101, 2)

Question 11

How do you exit a Loop?

Answer 11

For both FOR and WHILE Loops, the Break Statement is used to exit loops before they would exit on their own.

Question 12

Can I put a Function in a Function?

Answer 12

Yes - But think about whether that bit of code could be used on it’s own. If so, you might want to make it its own Function instead.

Question 13

Can I call **kwargs and *args something different?

Answer 13

Yes

**kwargs and *args are Standard, if you feel like calling them something different, you can do so. It does make your code a bit hard to read though for others that may want to work with you later, so only do this if it’s absolutely necessary.

Question 14

Can Functions call themselves?

Answer 14

Yes - It’s called Recursion, and is more advanced.

Question 15

How are values passed into Functions?

Answer 15

Parameters - Values are passed into functions through Parameters.

Question 16

When is a Variable in Scope?

Answer 16

Variables are IN Scope when you can reference it, they can be referenced in a LIST.

Question 17

What do *args and **kwargs do?

Answer 17

Allows you to pass a varying number of Parameters into a Function.

Question 18

What’s the deal with “pop”? It seems like an odd term. Why not “Remove”?

Answer 18

This is Programming terminology - many times when languages are being written, lists are written with pop and push functions.

Question 19

Are Dictionaries used in all programming languages?

Answer 19

They aren’t Unique to just Python, but they’re often called different things in other languages.
Hash Maps, Hash Tables, or associative arrays to name some.

Question 20

What pairs do you store in Dictionaries?

Answer 20

Keys and Values

Question 21

Which of the following is true?

Keys are always Unique
Values are always Unique
Both Keys and Values must be Unique
Neither Keys nor Values have to be Unique

Answer 21

Keys are always Unique

If you store a new Value under an existing Key, the Current Value under that Key will be overwritten.

Question 22

How do you get all the Keys out of a Dictionary?

Answer 22

keys()

Question 23

How do you store a new Value in a Dictionary?

Answer 23

dict [‘Key’] = ‘NewValue’