In [1]:
import numpy as np
import babypandas as bpd
import pandas as pd

Lecture 27 – Review, Conclusion¶

DSC 10, Winter 2025¶

Agenda¶

  • More review of old exam problems.
  • Working on personal projects.
  • Demo: Gapminder 🌎.
  • Some parting thoughts.

More review¶

Ask some questions! 🙋‍♀️🙋‍♂️¶

We'll take some time to work on past exam questions. Feel free to ask about specific topics you want more practice with, or specific problems you've tried that you want me to explain.

Personal projects¶

Using Jupyter Notebooks after DSC 10¶

  • You may be interested in working on data science projects of your own.
  • In this video, we show you how to make blank notebooks and upload datasets of your own to DataHub.
  • After this quarter, depending on the classes you're enrolled in, you may not have access to DataHub. Eventually, you'll want to install Jupyter Notebooks on your computer.
    • Anaconda is a great way to do that, as it also installs many commonly used packages.
    • You may want to download your work from DataHub so you can refer to it after the course ends (though you can look at it on Gradescope too).
    • Remember, all babypandas code is regular pandas code, too!

Finding data¶

These sites allow you to search for datasets (in CSV format) from a variety of different domains. Some may require you to sign up for an account; these are generally reputable sources.

Note that all of these links are also available at rampure.org/find-datasets.

  • Data is Plural
  • FiveThirtyEight.
  • CORGIS.
  • Kaggle Datasets.
  • Google’s dataset search.
  • DataHub.io.
  • Data.world.
  • R datasets.
  • Wikipedia. (Use this site to extract and download tables as CSVs.)
  • Awesome Public Datasets GitHub repo.
  • Links to even more sources.

Domain-specific sources of data¶

  • Sports: Basketball Reference, Baseball Reference, etc.
  • US Government Sources: census.gov, data.gov, data.ca.gov, data.sfgov.org, FBI’s Crime Data Explorer, Centers for Disease Control and Prevention.
  • Global Development: data.worldbank.org, databank.worldbank.org, WHO.
  • Transportation: New York Taxi trips, Bureau of Transportation Statistics, SFO Air Traffic Statistics.
  • Music: Spotify Charts.
  • COVID: Johns Hopkins.
  • Any Google Forms survey you’ve administered! (Go to the results spreadsheet, then go to “File > Download > Comma-separated values”.)

Tip: if a site only allows you to download a file as an Excel file, not a CSV file, you can download it, open it in a spreadsheet viewer (Excel, Numbers, Google Sheets), and export it to a CSV.

Demo: Gapminder 🌎¶

plotly¶

  • All of the visualizations (scatter plots, histograms, etc.) in this course were created using a library called matplotlib.
    • This library was called under-the-hood everytime we wrote df.plot.
  • plotly is a different visualization library that allows us to create interactive visualizations.
  • You may learn about it in a future course, but we'll briefly show you some cool visualizations you can make with it.
In [13]:
import plotly.express as px

Gapminder dataset¶

Gapminder Foundation is a non-profit venture registered in Stockholm, Sweden, that promotes sustainable global development and achievement of the United Nations Millennium Development Goals by increased use and understanding of statistics and other information about social, economic and environmental development at local, national and global levels. - Gapminder Wikipedia

In [16]:
gapminder = px.data.gapminder()
gapminder
Out[16]:
country continent year lifeExp pop gdpPercap iso_alpha iso_num
0 Afghanistan Asia 1952 28.801 8425333 779.445314 AFG 4
1 Afghanistan Asia 1957 30.332 9240934 820.853030 AFG 4
2 Afghanistan Asia 1962 31.997 10267083 853.100710 AFG 4
3 Afghanistan Asia 1967 34.020 11537966 836.197138 AFG 4
4 Afghanistan Asia 1972 36.088 13079460 739.981106 AFG 4
... ... ... ... ... ... ... ... ...
1699 Zimbabwe Africa 1987 62.351 9216418 706.157306 ZWE 716
1700 Zimbabwe Africa 1992 60.377 10704340 693.420786 ZWE 716
1701 Zimbabwe Africa 1997 46.809 11404948 792.449960 ZWE 716
1702 Zimbabwe Africa 2002 39.989 11926563 672.038623 ZWE 716
1703 Zimbabwe Africa 2007 43.487 12311143 469.709298 ZWE 716

1704 rows × 8 columns

The dataset contains information for each country for several different years.

In [19]:
gapminder.get('year').unique()
Out[19]:
array([1952, 1957, 1962, 1967, 1972, 1977, 1982, 1987, 1992, 1997, 2002,
       2007], dtype=int64)

Let's start by just looking at 2007 data (the most recent year in the dataset).

In [22]:
gapminder_2007 = gapminder[gapminder.get('year') == 2007]
gapminder_2007
Out[22]:
country continent year lifeExp pop gdpPercap iso_alpha iso_num
11 Afghanistan Asia 2007 43.828 31889923 974.580338 AFG 4
23 Albania Europe 2007 76.423 3600523 5937.029526 ALB 8
35 Algeria Africa 2007 72.301 33333216 6223.367465 DZA 12
47 Angola Africa 2007 42.731 12420476 4797.231267 AGO 24
59 Argentina Americas 2007 75.320 40301927 12779.379640 ARG 32
... ... ... ... ... ... ... ... ...
1655 Vietnam Asia 2007 74.249 85262356 2441.576404 VNM 704
1667 West Bank and Gaza Asia 2007 73.422 4018332 3025.349798 PSE 275
1679 Yemen, Rep. Asia 2007 62.698 22211743 2280.769906 YEM 887
1691 Zambia Africa 2007 42.384 11746035 1271.211593 ZMB 894
1703 Zimbabwe Africa 2007 43.487 12311143 469.709298 ZWE 716

142 rows × 8 columns

Scatter plot¶

We can plot life expectancy vs. GDP per capita. If you hover over a point, you will see the name of the country.

In [25]:
px.scatter(gapminder_2007, x='gdpPercap', y='lifeExp', hover_name='country')

In future courses, you'll learn about transformations. Here, we'll apply a log transformation to the x-axis to make the plot look a little more linear.

In [27]:
px.scatter(gapminder_2007, x='gdpPercap', y='lifeExp', log_x=True, hover_name='country')

Animated scatter plot¶

We can take things one step further.

In [29]:
px.scatter(gapminder,
           x = 'gdpPercap',
           y = 'lifeExp', 
           hover_name = 'country',
           color = 'continent',
           size = 'pop',
           size_max = 60,
           log_x = True,
           range_y = [30, 90],
           animation_frame = 'year',
           title = 'Life Expectancy, GDP Per Capita, and Population over Time'
          )

Watch this video if you want to see an even-more-animated version of this plot.

Animated histogram¶

In [35]:
px.histogram(gapminder,
            x = 'lifeExp',
            animation_frame = 'year',
            range_x = [20, 90],
            range_y = [0, 50],
            title = 'Distribution of Life Expectancy over Time')

Choropleth¶

In [37]:
px.choropleth(gapminder,
              locations = 'iso_alpha',
              color = 'lifeExp',
              hover_name = 'country',
              hover_data = {'iso_alpha': False},
              title = 'Life Expectancy Per Country',
              color_continuous_scale = px.colors.sequential.tempo
)

Parting thoughts¶

From Lecture 1: What is "data science"?¶

Data science is about drawing useful conclusions from data using computation. Throughout the quarter, we touched on several aspects of data science:

  • In the first 4 weeks, we used Python to explore data.
    • Lots of visualization 📈📊 and "data manipulation", using industry-standard tools.
  • In the next 4 weeks, we used data to infer about a population, given just a sample.
    • Rely heavily on simulation, rather than formulas.
  • In the last 2 weeks, we used data from the past to predict what may happen in the future.
    • A taste of machine learning 🤖.
  • In future DSC courses – including DSC 20 and 40A – you'll revisit all three of these aspects of data science.

Thank you!¶

  • This course would not have been possible without...
    • Graduate TA: Ashley Ho.
    • Undergraduate tutors: Eric Chen, Jiaying Chen, Jack Determan, Kate Feng, Francisco Franco, Charlie Gillet, Michelle Hong, Jason Huynh, Minchan Kim, Avi Mehta, Kathleen Nguyen, Athulith Paraselli, Pallavi Prabhu, Pranav Rajaram, Sofia Tkachenko, Bill Wang, Sophie Wang, Raymond Williams, Ylesia Wu, Ciro Zhang.
  • Learn more about tutoring – it's fun, and you can be a tutor as early as your 3rd quarter at UCSD!
  • Keep in touch! dsc10.com/staff
    • After grades are released, we'll make a post on Ed where you can ask course staff for advice on courses, data science, and UCSD more generally

Good luck on your finals!¶

See you tomorrow at 7PM in Center 101.¶

Study well 📚, eat dinner 🍴, and take a walk 🚶‍♀️ beforehand so you're ready to focus.¶