Problem Set 1#

See “Check Your Understanding” from Basics and Collections

Question 1#

Below this cell, add

  1. A Markdown cell with

    • two levels of headings;

    • a numbered list (We ask for a list in Markdown, not a Python list object);

    • an unnumbered list (again not a Python list object);

    • text with a * and a - sign (hint: look at this cell and escape characters)

    • backticked code (see adam-p/markdown-here)

  2. A Markdown cell with

Question 2#

Complete the following code, which sets up variables a, b, and c, to find the roots using the quadratic formula.

\[ x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} \]

Note: because there are two roots, you will need to calculate two values of x

a = 1.0
b = 2.0
c = 1.0
# Your code goes here

Question 3#

In the cell below, use tab completion to find a function from the time module that displays the local time.

Use time.FUNC_NAME? (where FUNC_NAME is replaced with the name of the function you found) to see information about that function, then call the function. (Hint: look for something involving the word local).

import time
# Your code goes here
# time. # uncomment and hit <TAB> to see functions

Hint: if you are using an online jupyter server, the time will be based on the server settings. If it doesn’t match your location, don’t worry about it.

Question 4#

Create the following variables:

  • D: A floating point number with the value 10,000

  • r: A floating point number with the value 0.025

  • T: An integer with the value 30

Compute the present discounted value of a payment (D) made in T years, assuming an interest rate of 2.5%. Save this value to a new variable called PDV and print your output.

Hint: The formula is

\[ \text{PDV} = \frac{D}{(1 + r)^T} \]
# Your code goes here

Question 5#

How could you use the variables x and y to create the sentence Hello World ?

Hint: Think about how to represent a space as a string.

x = "Hello"
y = "World"
# Your code goes here

Question 6#

Suppose you are working with price data and come across the value "€6.50".

When Python tries to interpret this value, it sees the value as the string "€6.50" instead of the number 6.50. (Quiz: why is this a problem? Think about the examples above.)

In this exercise, your task is to convert the variable price below into a number.

Hint: Once the string is in a suitable format, you can call float(clean_price) to make it a number.

price = "€6.50"
# Your code goes here

Question 7#

Use Python formatting (e.g. print(f"text {somecode}") where somecode is a valid expression or variable name) to produce the following output.

The 1st quarter revenue was $110M
The 2nd quarter revenue was $95M
The 3rd quarter revenue was $100M
The 4th quarter revenue was $130M

# Your code goes here

Question 8#

Define two lists y and z.

They can contain anything you want.

Check what happens when you do y + z. When you have finished that, try 2 * x and x * 2 where x represents the object you created from y + z.

Briefly explain.

y = [] # fill me in!
z = [] # fill me in!
# Your code goes here