Plotting data models

With the help of the numpy and pandas modules, FastAPI services can generate and render different types of graphs and charts using the matplotlib utilities. Like in the previous discussions, we will utilize an io.ByteIO stream and StreamResponse to generate graphical results for the API endpoints. The following API service retrieves survey data from the repository, computes the mean for each data strata, and returns a line graph of the data in PNG format:

from io import BytesIO
import matplotlib.pyplot as plt
from survey.repository.answers import AnswerRepository
from survey.repository.location import LocationRepository
@router.get("/answers/line")
async def plot_answers_mean():
    x = [1, 2, 3, 4, 5, 6, 7]
    repo_loc = LocationRepository()
    repo_answers = AnswerRepository()
    locations = await repo_loc.get_all_location()
    temp = []
 ...