Part C1: The First Program: print statements and comments

1. Open the file helloWorld.py with your preferred text editor (Click here for options) and read through the comments.
2. Make the changes as instructed in the script, save these changes, and exit out of the text editor.
3. Run helloWorld.py . There are two ways to run a script:
   ./helloWorld.py
   or call python explicitly
   python helloWorld.py
   . The first method requires that you have execute permission to the script and that the script has the proper shebang for python 3. For our FRI cluster, the shebang for python 3 is
   #!/usr/bin/env python
   . Note that this is not a comment if it's the first line of a file!
4. You should see that "hello world!" is printed on your screen like this:
   

1. Open your python script your_script.py using your editor of choice.
   
   
2. Adding comments to scripts you write is good practice. By doing this you will be able to understand the purpose of script you write and it will help you stay organized! Comments start with a '#' followed by text. Write a comment which says "Part C1" to indicate that part of the assignment you are working on.
   
   
3. (Assignment problem 1) Let's start with the simplest program; get your script to print "Part C1". Note that the quotation marks are not meant to be printed. The print function is a python built-in function. This function is used in hello_world.py and you can copy that line over, change the content between quotation marks.
   
   
4. (Assignment problem 2) Next, get your script to print "hello, my name is (enter name here)". Note that the perenthesis are not meant to be printed.
   
   
5. (Assignment problem 3) Finally get your script to print a blank line. Be sure to run this script after editing to make sure you have correctly coded these new print statements. Your script output should be similar to this:
   
   
   

Part C2: Variables

1. (Assignment problem 4) Go to your_script.py and find the section for part C2. Assign values to these 4 variables: my_name, my_age, pi, and do_longhorn_rule. The values should have the following types respetively: string, integer, float, float and boolean. Note that Python keywords for boolean values are case-sensitive:
   True
   or
   False
   
   
   
2. (Assignment problem 5) Next, print four lines which include each variable's name, the variable's corresponding value, and the type of value. Each line of the output should look like this: "my_age is 9001. It's type is . Note that the python print() function can take in multiple arguments seperated by commas, such as
   print(argument0,argument1,argument2)
   . The argument can be the return value of a function such as type(). For example,
   print( type(myst_var))
   first parses the variable "myst_var" to function type(), who returns a value that is then parsed to the print() function.
   
   
3. Run your script to see if the variables are getting the correct values and types. Remember that you should always include some descriptive strings in your print() statements to remind yourself what is being printed out.
   
   

Part C3: Arithmetic Operators

1. (Assignment problem 7) Go to your_script.py and find the section for part C3. Calculate your age in year 2049 and store the result as a variable called "my_age_in_2049". Print your age in 2049 by using the newly assigned variable.
   
   
2. (Assignment problem ) Add 1 to the variable my_age and assign the result back to the variable my_age. Print what the variable is after an increment of 1.
   
   
3. So far we have been only creating and executing scripts, a series of commands within a file with a .py extension that are executed. In Python we also have the ability to program through the interactive mode where you can write and execute your code line by line giving you immediate feedback. We will be primarily using scripts in this course. However, interactive mode can be a great learning tool, and I would encourage you to use it as you are learning Python. In addition, the interactive mode can function as a calculator. You can use interactive mode directly through python or through iPython. Try using the interactive mode to practice Python arithmetic.
   
   
4. Python the programming language has an order of operations when doing arithmetic. The rules are the same as what we've always used in algebra. The following is a list of operators which are order from the highest priority (first operations executed) to last priority (last operation executed):
   
   
   1. Parentheses
   2. Exponentionals
   3. Multiplication, division, and remainder
   4. Addition and subtraction
   
   Note: Operators with the same priority are evaluated left to right.
   
   (Assignment problem 11) You are provided a variable "x". First, using a pen and paper, calculate what the python operation (x+2)*(3+4)%2**5/5 should be when x is 1. Then write the code to do this calculation and store the results in the variable y. Print the value of y to see if you were correct.
   
   
5. (Assignment problem 12) Print the area of a 12 inch pizza using the pi variable and store the results in the variable "area".
   
   
6. (Assignment problem 15) Print the total energy of a 5 kg weight that has a velocity of 2 m/s, and is at a height of 5 m. If you forgot how to calculate kinetic energy and gravitational potential energy,
   what should you do?
   

   Ask Dr. Google or professor ChatGPT.
   Use 9.8 for g. Store the results in a variable called "energy".

Part C4: Built-in Functions and Python Modules -- Math and Numpy

1. (Assignment problem 16) Go into the Your_script directory, open your_script.py, and print "Part C4" at the bottom of this script.
   
   
2. Print the variable my_age then use Python's built in functions to convert my_age to a float. Print the new my_age variable. Then, print a string which describes how you can tell the difference between an integer and a float without using the type function.
   
   
3. (Assignment problem 17) Import the math and/or numpy module. Use one of these modules to compute and print the square root of 36.
   
   
4. (Assignment problem 18) Compute and print e³ + e^-2 using the math or numpy module and arithmetic operators.
   
   
5. (Assignment problem 19) Compute the total energy of an object which weighs 10 kg and has a velocity of 5 m/s and has 0.5 Kilojoules of potential energy using the numpy or math module to compute the power function (v²). Set this value to a variable called total_energy and print this variable.

Part C5: Creating Your Own Functions

1. (Assignment problem 20) Go into the Your_script directory, open your_script.py, and print "Part C5" at the bottom of this script.
   
   
2. (Assignment problem 21) Create a function with the name print_hello that takes no arguments and prints the string, 'Hello!'. Call this function to make sure it is working properly.
   
   
3. (Assignment problem 22) Create a function with the name print_age which takes one argument, my_age, and prints the string 'I am', my_age,'years old'. Call this function to make sure it is working properly.
   
   
4. (Assignment problem 23) Create a function called compute_kinetic_energy which takes two arguments, mass and velocity, and returns (See chapter 6.1) the kinetic energy of this object. To test this function set the output to a variable called kinetic_energy and use a mass of 10 kg and 10m/s. Then, print the variable kinetic_energy.
   
   
5. (Assignment problem 24) You can create functions which call other functions. Create a function called print_kinetic_energy which takes two arguments, mass and velocity, and prints the kinetic energy of an object. Use the function compute_kinetic_energy to compute the kinetic energy. To test this function, call print_kinetic_energy using a mass of 10 kg and a velocity of 10m/s.
   
   
6. (Assignment problem 25) You can also create a function that returns multiple arguments. Create a function called energy that takes the variables mass, velocity, and height. Have this function return the kinetic energy, potential energy and total energy of an object using the equations given in part C3 question 9. To test this function call energy using mass = 5 kg, velocity = 3 m/s, and height = 10m. Store the output in variables ke1, pe1, and te1. Print all three variables.

Part C6: Boolean Operators

1. (Assignment problem 26) Go into the Your_scripts directory and at the bottom of this script print "Part C6".
   
   
2. (Assignment problem 27) Use a relational operator to determine if you are 25 years old (print True) or not (print False).
   
   
3. (Assignment problem 28) Use a relational operator and your function compute_kinetic_energy to determine if the kinetic energy of an object with mass 5 kg and velocity 10 m/s is less than or equal to an object with mass 3 kg and velocity 11 m/s.
   
   
4. (Assignment problem 29) Create a function called greater_than_5_and_even with one argument, x. This function should return a boolean (True or False) indicating if the an argument x is greater than 5 and even. You should use logical and relational operators as well as arithmetic to determine this. Test your function and print your results for the following values of x: 3, 4, 6, and 7.

Part C7: Conditional Execution

1. (Assignment problem 30) Go into the Your_scripts directory and at the bottom of this script print "Part C7".
   
   
2. (Assignment problem 31) Create a function called even_or_odd which takes one argument, an integer. This function should print 'even' or 'odd' depending on if the integer is even or odd. Test this function with the integers 10 and 11.
   
   
3. (Assignment problem 32) Next you will create a function which utilizes the Pythagorean theorem. Create a function called is_sidec_5 which takes two arguments, a and b, the two shortest lengths of the sides of a right triangle. Your function should compute the length of the third side of the triangle and print 'side c is less than 5', 'side c is equal to 5' or 'side c is greater than 5'. Test your function using the following values of a and b and print the output:
   
   
   1. a = 3; b = 4
   2. a = 1; b = 2
   3. a = 4; b = 6
   
   
4. One equation which approximates the interaction of a diatomic molecule is the Morse potential. You can find the equation for the Morse potential on wikipedia. You can plot this function HERE. On this webpage enter the equation for the morse potential, the key word 'plot' and 'range(0.5,5.0)'. Here are a few programming exercises to do with this potential:
   
   
   1. Create a function called morse_potential_energy which takes three variables, the bondlength of a diatomic (r), the equilibrium or optimal bondlength (r_e), and the energy required to break a bond in a diatomic (D_e). Set the a equal to 5. Have this function return the potential energy of the morse potential.
      
      
   2. Create a second function called status_of_bond that takes one variable, the bondlength. Use a value of D_e equal to 1.0 eV and r_e equal to 1.0 Angstroms. (Assignment problem 33) Get this function to print whether the given bondlength is 'compressed', 'ideal', 'stretched', or 'broken'. You must use two conditions: 1, r is greater than r_e and 2, the potential energy (think about what the potential energy should be) to determine if the bond is broken or stretched. There is not one correct solution for distinguishing between a broken and stretched bond, but you should select a reasonable value. Test this function with the following values of r:
      
      
      1. r = 0.5
      2. r = 1.0
      3. r = 1.5
      4. r = 6.0
   
   

Part C8: Lists