Unit 4 Python Loops and Lists

Show how to use "break" and "continue" statements to halt a loop or loop iteration early

If you use the break the code will stop, if you use the continue the code will continue and proceed as normal

When is the logical expression tested in a "while" loop?

When its true

What happens if the "while" loop's logical expression is False when first tested? Will the loop run at all?

Yes, it will only run when false though

How would you write a "for" loop to iterate over all of the values in a list or tuple?

for var in range: print(var)

Know how to use the "for" loop to iterate over the contents of a list, tuple or string or a specific numeric range

if var != "STOP" then the code will continue

What is the result of the "in" logical expression? How do you use it in an "if" statement?

if x is in y: it is there just to tell you what is in the code and if it is then it executes the code

How do you access the individual values of the list or tuple from within the loop body?

index

insert()

Adds an element at the specified position

append()

Adds input to the end of a list

How do you call those three functions with an input parameter?

After you have the input with the variable, you then go down another line and apply what you want to the variable

What is the purpose of the "continue" statement and how does it affect a "for" loop?

It makes the code keep going, and you then have to put more stuff in it.

How do ranges allow you to read a sequence of list elements?

It only shows you what the range is it shows you the little number but stops at the big number so if you have (1, 4) it will print out 1, 2, 3 and not show 4.

How do you use the "in" keyword to form a logical expression with a list?

It shows for what's "in" the code

What is the purpose of the "break" statement and how does it affect a "for" loop?

It stops the rest of the code

What is an infinite loop and why is it a bad thing?

It will crash your computer

Know how to use the "in" keyword to search an input list, tuple or string for a value

It will show you whatever you have to be a Boolean if its true or false.

How do index values work to access specific list elements?

Its in numbers

Understand the need for lists to manage many values at once

Lists are there for if you need many answers for a variable, but don't want a lot of variables, or need to just choose one choice and there be no point in all the other variables.

Does each element need to be the same data type?

No

When using a range, does the output contain the element at the ending index?

No

What kinds of data can you store in lists?

Numbers or words, or even letters.

reverse()

Reverses the order of the list

What is the purpose of the "else" statement and when does the "else" body execute? When would it be skipped?

The else statement is there if the thing isn't true you use it as a backup, and it would be skipped if the for in the loop is true.

Know how to use a final "else" block to execute logic after the loop ends successfully

The final else is there so the code will end and you won't have a infinite loop, because you eventually will get to the else statement

Know how to initialize a list with values

The lists start off with the number 0 and work there way up to whatever number, or how much stuff you have in the list.

What is the expected output from each of the three functions?

The numbers?

What is the biggest difference between a tuple and a list?

The parenthesis

How is a "while" loop different than a "for" loop?

The while loop is there for user input, for loops don't need user input.

Know how to print lists

There are two ways, you can either just print out the lit name, or you can do the list name and the number that you want to print out.

What is the purpose of each of the following list functions? What are the required input parameters?

They are their to make stuff easier

Understand how loops are used in programs

They are used to keep looping, if the conditional isn't right

How do you identify the statements in the body of a "while" loop?

They will be indented, and will only run when its true, if its not then it will just run.

sort()

To arrange data alphabetically, numerically, or chronologically.

Why would you need to store a group of items in a single variable?

To make it to where you don't need to make a tone of variables, also to make your life easier

How do you declare a tuple instead of a list?

Tuples are surrounded by, ( ) while lists are [ ]

How do you ensure that your loops are not infinite?

You add a else statement in you conditional, to make it then stop

Know how to identify and avoid "infinite loops"

You avoid the infinite loops, by making the eventual out statement

Know how to use functions specific to the list and tuple data types to add, remove and modify list elements

You can us the list function that best fits what you want to do to your list

Know how to create at tuple

You create a tuple by adding a comma. It makes it easier to make for lists, and adding lists to your str()

How do you use a "for" loop to iterate over all of the characters in a string?

You print the list

Understand the difference between a list and a tuple and when to use each

You use a list to make multiple things in a line, and you use a tuple to add the list to the string, or output that you want.

What is the purpose of a "for" loop?

a for loop is used to perform a program loop a fixed number of times

clear()

clears the whole list

How do you use a "for" loop to iterate over all of the numeric integers in a range?

count

count()

counts how many items are in the list

pop()

deletes the specific item

Which three Python functions will work on any list or tuple?

index, count, and in

Know how to create a "do-while" (bottom-tested) loop using "while" syntax

it will only do that piece of code while the thing is true

Know how to use len(), min() and max() functions on input lists and tuples

len() shows how many things you have in the list, min() will show you the closest letter to a, and max() will show you the closest letter to z.

index()

lists the stuff in alphabetical order

For any given list size, what is the minimum and maximum valid index value?

minimum is 0, and max is to whatever you have, it keeps going.

Know how to access individual elements and ranges with index values

name.index(number)

How do you print list contents?

print(var)

How do you specify the lower and upper bounds of a numeric range? Is the upper bound inclusive?

range or in

remove()

removes items from list

Demonstrate the syntax for a Python "for" loop

the for is there to help you with your code better, it is also part of the thin that makes the code loop

How do you create a list in Python?

var = ["thing" , "that", "goes", "in", "list"]

Define a "while" loop that will execute as long as a logical expression is true

while True:

Know how to apply "break", "continue" and "else" statements to a "while" loop

you break by putting the break in the for loop, same for the continue and else statements in the for loop