This Matplotlib Intro lesson is for a beginner. Read the short notes, run each example, then change one name or number and run it again.
Matplotlib draws charts from sequences of numbers. A line chart needs an x sequence and a y sequence of the same length.
The runner does not import matplotlib. The example prepares the pairs a plot would use.
Example 1: Start here
Locally, import matplotlib.pyplot as plt, then plt.plot(hours, scores) and plt.show().
hours = [1, 2, 3, 4] # a list; the values stay in this order
scores = [40, 55, 70, 82] # a list; the values stay in this order
print(list(zip(hours, scores))) # zip keeps each pair together
Example 2: List the points
Matplotlib Intro draws points. Printing each pair lets you check the data before a chart library plots it.
points = [(1, 19), (2, 12), (3, 18)] # a list; the values stay in this order
for x, y in points: # repeat the indented lines once per value
print(x, y) # a comma prints each value, with a space between
Example 3: Find the highest bar
The tallest bar is the largest number. max does that lookup.
heights = [19, 12, 18] # a list; the values stay in this order
print(max(heights)) # the largest value
Example 4: Label each point
A chart label belongs with its number. zip keeps each day next to its height.
labels = ["Mon", "Tue", "Wed"] # a list; the values stay in this order
heights = [19, 12, 18] # a list; the values stay in this order
for label, height in zip(labels, heights): # repeat the indented lines once per value
print(label, height) # a comma prints each value, with a space between
Locally, import matplotlib.pyplot as plt, then plt.plot(hours, scores) and plt.show().
