Python: TurtleWorld and Polygons

In this blog post, I will be continuing on with the TurleWorld and seeing if I can make different shapes and objects using my previous knowledge and guidance from the book. For example, in the first exercise, it wants me to simplify my coding by adding a “for” statement. “A for statement is sometimes called a loop because of the flow of execution runs through the body and then loops back to the top” (Downey 39). In this case, I used the “for” statement to simplify and make my square coding not as repetitive. 

In this example, I had the line of code that I used in the last post to repeat 4 times, instead of me typing it out 4 times. In the next exercise in Think Python. It wants me to fiddle around with the angle of the turns that the turtle can make. In this case, by making the polygon a function, I can change around what I can input in its parameters to change the shape that I make with the Turtle. In the example that Think Python gives me, the first line of code defines the function “polygon” to have the variables, t, n, and length. Then in the function of the polygon, there is a variable called angle, which calculates the exterior angle of the polygon. Then there is a loop statement again that moves the turtle (t) in a certain length, and then turns the turtle left in a certain angle. The last line of the code executes the function “polygon” with 7 sides with each side length being 70 (Downey 39).

During the next examples in Think Python there was also a challenge to program it so that the turtle draws a circle. While I tried my best to figure it out I eventually ran out of time and gave up to be able to post on the blog on time.

Question: When have you given up on something because it was too difficult?

Downey, Allen B. Think Python: How to Think like a Computer Scientist. Sebastopol: O'Reilly Media, 2015. Print

Python: Modules and TurtleWorld

 Most programming languages include modules in them, like Python. “Modules [are] a file that contains a collection of related functions” (Downey 24). For example, there is already a built-in module in Python called “math”. The math module imports lots of functions into the program so that you can reference them in your code. An example of this would be when you import the math function, you can access difference new functions such as square roots, pi, and logarithms.

In the book “Think Python, Chapter 4” it tells to download a package called “Swampy”. Packages are just a collection of modules that you can install, since modules are collections of new functions, packages are in essence adds lots of new functions into the programming language (Downey 37). In Swampy there is a module that is called TurtleWorld. Using this you can create a “TurtleWorld” which is a window where a “Turtle” will draw what you tell it to draw. For example in the code below, the first line imports all the functions from the TurtleWorld module from the Swampy package. Then the next lines in the script make a TurtleWorld called world, and a Turtle called bob. Using this we can use bob and the TurtleWorld to draw a square and other shapes as we want. The “fd” function moves the Turtle “bob” forward 100, and the “lt” function turns him to the left. Repeat this 3 more times and we have a square.

From this experience, I was surprised the capabilities of Python and what it can accomplish, specifically with the TurtleWorld modules.

 Question: What are some things that you were surprised you can accomplish?

Downey, Allen B. Think Python: How to Think like a Computer Scientist. Sebastopol: O'Reilly Media, 2015. Print

Lists Done With Functions in Python

In the book Python Crash Course I learned how to use functions in Python and implement them into lists. It explains this on page 134, "When you want to perform a particular task that you've defined in a function you call the name of the function responsible for it." (Matthes 134). This taught me how to use functions in Python which simplifies my code to be more clean.
I also learned how to format my text with functions. This is explained on page 141, Functions can store values and format them to be more neat (Matthes 141). This taught me how to change format values I already have with a function which diversifies what I can do in Python.
How would you create your lists in Python?

Matthes, Eric. Python Crash Course: A Hands-on, Project-based Introduction to Programming. San Francisco: No Starch Press, 2016. Print.

Lists Done With a While Loop in Python

In the book Python Crash Course I learned how to use while loops in Python and apply it to lists. It explains what while loops are on page 122 it says, A while loop is a loop that runs as long as a value set in the loop is true. (Matthes 122). This taught me how to easily implement while loops into my code which helps me learn more of what I can do in Python.
I also learned how to stop a while loop before its condition is false. This is explained on page 125, "To exit a while loop immediately without running any remaining code in the loop, regardless of the results of any conditional test, use the break statement" (Matthes 125). This taught me how to implement a statement that can stop the loop which helps me improve at programming in the Python language.
What other programming language should I learn about?

Matthes, Eric. Python Crash Course: A Hands-on, Project-based Introduction to Programming. San Francisco: No Starch Press, 2016. Print.

List Done With a Dictionary in Python

In the book Python Crash Course I learned how to use dictionaries in Python and apply it to lists. It explains this on page 96, Dictionaries are a collection of pairs, the first part of the pair is a name while the second part is the value the name is associated with (Matthes 96). This taught me how to utilize other methods to create lists which helps me diversify how I program in Python.
I also learned how to add new pairs to dictionaries after making it. It also explains this on page 97, "To add a new key-value pair, you would give the name of the dictionary followed by the new key in square brackets along with the new value" (Matthes 97). This taught me how to improve upon dictionaries which helps me improve at programming in Python.
What program should I do next in Python?

Matthes, Eric. Python Crash Course: A Hands-on, Project-based Introduction to Programming. San Francisco: No Starch Press, 2016. Print.

Python:Functions

In Python and in almost all programming languages there are these commands called functions. “In the context of programming, a function is a named sequence of statements that performs a computation” (Downey 23). This is very useful in programming since if there is a repetitive sequence of code that we want to execute, instead of repeating the same lines over and over again we can make a function for that sequence of code so that we can call on it when we need to. In Python, there are already many different functions that are built into the program. However, there is also a way where we can add a function into our script. This is called a function definition. When we define a function and its sequence of code that executes whenever the function is being used (Downey 25).   

An example of this is

In the code, there is a keyword called “def”. This means that this is a function definition, the keyword "def" defines the line of code as a function. The text that is next to the “def” is the name of the function. In this example, the name of the function is called “print_lyrics”. Finally, the text under it is what the function contains and what it will do when it is executed. In this example, this function will print out the lines. Finally, the line of code at the end of the function executes the function (print_lyrics()). (Downey 26).

“I’m a lumberjack and I’m okay.”

“I sleep all night and I work all day.”

 Using this new found knowledge we can write a program that can draw a grid.

In this program, I made two functions that printed out a line of the grid. Then making a final function I printed out the grid.

Question: When have you found yourself having to do something repetitive?

Downey, Allen B. Think Python: How to Think like a Computer Scientist. Sebastopol: O'Reilly Media, 2015. Print.

Python-Interactive Mode and Script Mode

       In Python, there are two ways to code, one way in Interactive Mode and another way in Script Mode. While there are advantages to each both of them, there can be some disadvantages too, this is why you need to utilize both of them to be successful. The advantages to using Interactive mode is that you can test out bits of code to see if they work before you put them into your script. In script mode you can store multiple lines of code so that you can execute it all at once. There are also differences when you are coding in interactive mode and script mode that can also be confusing (Downey 17).

For example:

If you code this into the interactive mode then the output would show up under it

X=126

X*420

However if you type this exact code into script mode the output would be different

As you can see on the left side is the script, and when executed there was no output on the right, or the shell. This is because we didn’t tell Python to print out the output which is sometimes confusing as stated before. “But if you type the same code into a script and run it, you get no output at all. In script mode an expression, all by itself, has no visible effect. Python actually evaluates the expression, but it doesn’t display the value unless you tell it to:” (Downey 17).

  

Since we added the print command in the script there was a visible output like in the interactive mode.

Question: What are some other scenarios where you need more than one resource to be successful?

Downey, Allen B. Think Python: How to Think like a Computer Scientist. Sebastopol: O'Reilly Media, 2015. Print. 

More in Depth Lists in Python

I learned how to develop my lists even more and make them more in depth. In the book Python Crash Course it showed me how to use if statements, on page 76 it said, You can change specific elements by using an if statement. (Matthes 76). This taught me how to change specific elements in a list to be more in depth and precise which leads to me being better at programming in the Python language.
Another thing the book showed me how to do was display user input, on page 118 it said, "The input() function pauses your program and waits for the user to enter some text. Once Python receives the user's input, it stores it in a variable to make it convenient for you to work with." (Matthes 118). This taught me how to implement code that can interact with the user which helps me become better at programming in the Python language because interactive programs are very useful.
What types of programs do you think are most useful?

Matthes, Eric. Python Crash Course: A Hands-on, Project-based Introduction to Programming. San Francisco: No Starch Press, 2016. Print.

Lists in Python

Matthes, Eric. Python crash course: a hands-on, project-based introduction to programming. San Francisco: No Starch Press, 2016. Print.
I learned how to make lists in Python and display them in multiple ways. In the book Python Crash Course it showed me how to reverse lists, on page 49 it said, You can reverse lists by using the name that defines a list and adding .reverse() to it. After that line you type print(name) and it will be printed in reverse. (Matthes 49). This taught me how to implement reversed lists into my code which helps me improve at programming in the Python language. Another thing the book showed me how to do was separate list items, on page 38 it said, "Write the name of the list followed by the index of the item enclosed in square brackets." (Matthes 38). This taught me how to implement a list into my code that looks more professional when printed which helps me improve at programming in the Python language.

What do you think the most important programming language is?

Matthes, Eric. Python Crash Course: A Hands-on, Project-based Introduction to Programming. San Francisco: No Starch Press, 2016. Print.

Python-The Programming Language

Python is a programming language that is meant as an introduction to programming. It is classified as a high level language like some other programming languages such as C, C++, and Java. There are also low level languages, generally computers can only run low level language, but writing in these languages can be time consuming and hard. Writing in high level languages however can take less time to write and be simpler to read. After writing these high level languages there has to be an interpreter that converts this high level language into low level language for the computer to understand. This is a small disadvantage compared to the advantages that you get from the high level languages (Downey 1-2). Based on all of these factors Python is an excellent first programming language since it is very simple to read and understand compared to other languages and can be very powerful at the same time.

            When starting to learn how to program the traditional first program is the "Hello World!” program. This program displays the worlds “Hello World!” into the display. 

To write this program in Python it looks like this

However, when I first typed in the code I got results that looked like this.

This is because, I didn’t have apostrophe marks surrounding “Hello World!” this lead into an error classified as syntax error. “Python can only execute a program if the syntax is correct; otherwise, the interpreter displays an error message. Syntax refers to the structure of a program and the rules about that structure. For example, parentheses have to come in matching pairs, so (1+2) is legal, but 8) is a syntax error (Downey 4).” This made me realize what I did wrong and made me reevaluate my mistakes and learn from them. "The single most important skill for a computer scientist is problem solving. Problem solving means the ability to formulate problems, think creatively about solutions, and express a solution clearly and accurately (Downey 1).” While what I demonstrated above isn’t the most difficult of problems, it shows that problem solving is going to be a key skill for programming. This skill overall is going to be an important skill in life, as you might need to use problem solving in everyday scenarios.
Question: What are somethings that you do every day that require problem solving?

Downey, Allen B. Think Python: How to Think like a Computer Scientist. Sebastopol: O'Reilly Media, 2015. Print.