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Daily Challenge 2

Our goal was to write a function to display the first n numbers, in binary. Here is my solution:

Helpful Resources (Also at main page.)

So I know that we are facing some difficult tasks everyday in class: just jumping, in embracing the discomfort, and flailing around until things make sense. (If I haven't told you my dark room analogy for learning technical material ask me to when you read this line.)

In light of that, here are some resources you might find very helpful in trying to find your way around these magic words:

Class 3: If, True/False, and Logic

Now in the last class session we didn't finish the notes. We were up to for x in [1,2,3]:, so let's head there now and continue.

Intermission Gif

Boolean Expressions

When you hear the word Boolean you should think of a "True or False" expression. The word actually is derived from George Boole:

George Boole

Take a look at this insightful "Boolean" thought:

Beauty in Math

The basic words you should know are:

In Math we consider a statement as something with a truth value of True or False. Then we combine the statements using and and or to make bigger statements which are still True or False.

Boolean Task 1:

What is the truth value of the following statement:

It is Monday.

What is the truth value of this statement:

It is Monday OR two is less than one.

What is the truth value of this statement:

It is Monday AND two is less than one.

In Python we can build statements which evaluate to True or False. Either by using the words True and False or by asking it true/false questions using Boolean Operators:

The result will be True or False, and we can mix it all up with and and or.

Boolean Task 2: Decide (before hitting run) what the following nine print statements will display. Then run and confirm:

Boolean Task 3: Decide (before hitting run) what the following compound statement will display. Then run and confirm:

if elif else

The main uses for booleans are to decide when to run blocks of code (and how often to run them). Here is a simple example:

If Task 4: Change the value of number to trigger the "negative" message. What is the logical flaw in this program?

When you want to have many possible blocks you can use elif which is short for else if (doesn't work in Python but does in many other languages). Here is an example:

elif Task 5: Change the value of number (several times) to trigger each separate code block (sorry for my jokes). Change the structure so that the code does not check for negatives.

There is even an "inline" if which works like this. value1 if condition else value2

Here is an example: (I use the "modulo" operator a % m which gives the remainder when a is divided by m)

Putting it all together

Let's make a die rolling function, an is_even function, an inline if, and a for loop to roll a die 10 times:

Understanding Task 6: Read through that code and understand what is happening. Change the functions and their names so that we generate a random number from -10 to 10 and instead of even and odd we detect negative and non-negative.

DAILY CHALLENGE 3: Build a function which consumes a positive integer n and adds all of the odd positive numbers less than n. For example myfunc(6) will return 9 and myfunc(5) will return 4.