Assignment 2: Python Functions and Classes¶
Part I: Exploring the Python Standard Library¶
Skim the documentation for the datetime module
1. Import the datetime module¶
2. Create a datetime object for the day you were born¶
and print its representation in your notebook
3. Create a timedelta object representing 100 days, 10 hours, and 13 minutes¶
4. Verify that these two objects do not have the same type¶
Use an assert statement
5. Add the timedelta to the datetime¶
and assign it to a new variable
6. Display the month of the new date¶
7. Create a list of datetimes for all of your birthdays¶
beginning from your 1st birthday and ending on your most recent birthday. (Don't do this manually; use a loop or a list comprehension!)
2. Write a function to convert temperature to fahrenheit¶
Include an optional keyword argument to specify whether the input is in celcius or kelvin. Call your previously defined functions if necessary.
3. Check that the outputs are sensible¶
by trying a few examples
4. Now write a function that converts from farenheit¶
and uses a keyword argument to specify whether you want the output in celcius or kelvin
5. Write a function that takes two arguments (feet and inches) and returns height in meters¶
Verify it gives sensible answers
6. Write a function takes one argument (height in meters) and returns two arguments (feet and inches)¶
(Consult the tutorial on numbers if you are stuck on how to implement this.)
7. Verify that the "round trip" conversion from and back to meters is consistent¶
Check for 3 different values of height in meters
Part III: Modules¶
[This section is worth 6 points]
Put all of your above functions into a module called units.py. Create valid docstrings for each function.
Import the module. Verify that you can call the functions and view their docstrings.
Part IV: Classes¶
[This section is worth 6 points]
Write a class that represents a Planet. The constructor class should accept the arguments radius (in meters) and rotation_period (in seconds).
You should implement three methods:
surface_arearotation_frequency__eq__"magic/dunder method" used to test for equality between two planets (i.e.planet1 == planet2)
If you class works properly, it should pass all of the tests below:
earth = Planet(6.3781e6, 86400)
import pytest
assert earth.surface_area() == pytest.approx(5.112015e14)
assert earth.rotation_frequency() == pytest.approx(7.2722e-5)
earth2 = Planet(6.3781e6, 86400)
assert earth == earth2
jupyter = Planet(69.911e6, 9.925*60*60)
assert jupyter.surface_area() == pytest.approx(6.14187e16)
assert jupyter.rotation_frequency() == pytest.approx(1.758518e-4)