# For our example dataframe
import pandas as pd
# For our plot
import matplotlib.pyplot as plt

# Generating sample data
df = pd.DataFrame({"col1":range(10)})

# Creating a canvas for our plots
fig, axes = plt.subplots(1,1, figsize=(12,6))

# We plot with a label parameter that will be in our legend.
axes.plot(df["col1"], label="Column 1")
# We tell matplotlib we want a legend on our main plot
axes.legend()

# We make our canvas tidy and clean
plt.tight_layout()

# We show the graph
plt.show()