A trend line sample in matplotlib Python

trendline_drawing.py

# higher points are returned
while len(df_high)>2:
    slope, intercept, r_value, p_value, std_err = linregress(x=df_high['Number'], y=df_high['High'])
    df_high = df_high.loc[df_high['High'] > slope * df_high['Number'] + intercept]
    
df_high.tail()

# lower points are returned
while len(df_low)>2:
    slope, intercept, r_value, p_value, std_err = linregress(x=df_low['Number'], y=df_low['Low'])
    df_low = df_low.loc[df_low['Low'] < slope * df_low['Number'] + intercept]
    
df_low.tail()