Skip to content

Data Manipulation with pandas

Run the hidden code cell below to import the data used in this course.

1 hidden cell

Take Notes

Add notes about the concepts you've learned and code cells with code you want to keep.

Add your notes here

# Add your code snippets here

Explore Datasets

Use the DataFrames imported in the first cell to explore the data and practice your skills!

  • Print the highest weekly sales for each department in the walmart DataFrame. Limit your results to the top five departments, in descending order. If you're stuck, try reviewing this video.
  • What was the total nb_sold of organic avocados in 2017 in the avocado DataFrame? If you're stuck, try reviewing this video.
  • Create a bar plot of the total number of homeless people by region in the homelessness DataFrame. Order the bars in descending order. Bonus: create a horizontal bar chart. If you're stuck, try reviewing this video.
  • Create a line plot with two lines representing the temperatures in Toronto and Rome. Make sure to properly label your plot. Bonus: add a legend for the two lines. If you're stuck, try reviewing this video.

Calculating on a pivot table Pivot tables are filled with summary statistics, but they are only a first step to finding something insightful. Often you'll need to perform further calculations on them. A common thing to do is to find the rows or columns where the highest or lowest value occurs.

Recall from Chapter 1 that you can easily subset a Series or DataFrame to find rows of interest using a logical condition inside of square brackets. For example: series[series > value].

pandas is loaded as pd and the DataFrame temp_by_country_city_vs_year is available.

Calculate the mean temperature for each year, assigning to mean_temp_by_year. Filter mean_temp_by_year for the year that had the highest mean temperature. Calculate the mean temperature for each city (across columns), assigning to mean_temp_by_city. Filter mean_temp_by_city for the city that had the lowest mean temperature.

Answer:

# Get the worldwide mean temp by year
mean_temp_by_year = temp_by_country_city_vs_year.mean()

# Filter for the year that had the highest mean temp
print(mean_temp_by_year[mean_temp_by_year == mean_temp_by_year.max()])

# Get the mean temp by city
mean_temp_by_city = temp_by_country_city_vs_year.mean(axis ="columns")

# Filter for the city that had the lowest mean temp
print(mean_temp_by_city[mean_temp_by_city == mean_temp_by_city.min()])