Hi, my name is Ritika and I’m a senior instructor at Juni Learning! Welcome to this basic Python data science tutorial.
Today we’ll talk about how we can gather data and graph it in Python. Specifically, today we'll be working with survey data that we get beforehand from friends or family by asking what their favorite food is.
We’ll learn how to create bar graphs specifically using dataframes and the Seaborn package.
Who is this for?
Juni Level: Python 3
Coding Language: Python
Coding experience: Intermediate - Advanced
Challenge Level: Easy, assistance may be needed in using pandas.
Approx lines of code: ~15
Core concepts practiced:
Beginning data science
Using the Pandas package to create a dataframe
Prerequisite concepts to know/review:
Click run to see the project yourself below!
You can also view my project solution code if you get stuck.
Keep in mind:
We’ll be using dictionaries, so it’ll be important to see the relationship between dictionaries and dataframes, and how we can use data frames to graph things.
General order of steps to implement:
Gather data from family or friends, and put in in a dictionary.
Turn the dictionary into a data frame.
Graph the data.
Save the figure.
We can change some of the features of the graph as well.
How do we do each of these steps?
Step 1: Gather data from family and put in in a dictionary.
Ask around to see what peoples’ favorite foods are. It’s a good idea to have general categories so that we can have an easier time collecting data.
Hint: For example, instead of asking for specific flavors, we can ask people if they like pizza or ice cream and have them pick. Make sure to keep track of your data in one place. We’ll need this for the next step!
Create a dictionary using the data. The key will be a string which will be the food. The value will be the total number of people who voted the food as their favorite.
Step 2: Turn the dictionary into a data frame.
Before we continue, import
matplotlib.pyplot at the top of your code. This will ensure we have all the packages we need for our next step.
Convert the dictionary into a dataframe. We’ll use the
DataFrame() function in pandas to complete this step.
Step 3: Graph the data and save the figure.
We’ll be creating a bar plot to display our data; let’s use the
barplot() function and our dataframe to complete this. Remember, we have to save our figure as well.
Step 4: We can change some of the features of the graph as well.
Now we have a bar graph. Let’s see if we can change the title and the axes titles. Let’s save out barplot object in a different variable and use
set() to change our titles.
Now that we’ve changed our axes let’s take a look. Our bar graph is complete!
Want more of a challenge? Try adding these bonus features.
Changing the color scheme of the graph
Adding titles to the axes
This technique can be used for any survey – try it on other survey data!
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Thanks for watching and hope you had fun making this project with me!
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