This example shows how to make a line chart with several lines. Each line represents a set of values, for example one set per group. To make it with matplotlib we just have to call the plot function several times (one time per group).
# libraries
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
# Data
df=pd.DataFrame({'x_values': range(1,11), 'y1_values': np.random.randn(10), 'y2_values': np.random.randn(10)+range(1,11), 'y3_values': np.random.randn(10)+range(11,21) })
# multiple line plots
plt.plot( 'x_values', 'y1_values', data=df, marker='o', markerfacecolor='blue', markersize=12, color='skyblue', linewidth=4)
plt.plot( 'x_values', 'y2_values', data=df, marker='', color='olive', linewidth=2)
plt.plot( 'x_values', 'y3_values', data=df, marker='', color='olive', linewidth=2, linestyle='dashed', label="toto")
# show legend
plt.legend()
# show graph
plt.show()