matplotlib fill_between() 和 > 符号出现问题

Question

I am trying to use the fill_between() function from matplotlib for a graph I'm making. I used the exact code from the documentation ( https://matplotlib.org/3.2.1/gallery/lines_bars_and_markers/fill_between_demo.html#sphx-glr-gallery-lines-bars-and-markers-fill-between-demo-py ) but when I use it I get the following error:

fig, ax = plt.subplots(figsize=(16,8))
y1 = sns.lineplot('game_seconds_remaining', 'home_wp', data=vb, color='#4F2683',linewidth=2)
y2 = sns.lineplot('game_seconds_remaining', 'away_wp', data=vb, color='#FB4F14',linewidth=2)

x = plt.axhline(y=.50, color='white', alpha=0.7)

ax.fill_between(x, y1, y2, where=(y1 > x), color='C0', alpha=0.3, interpolate=True)

Output: TypeError: '>' not supported between instances of 'AxesSubplot' and 'AxesSubplot'

Why is this not working for me yet it works on the documentation? What I want to do is shade any area that dips below the horizontal line (x) and above it. Any help is greatly appreciated. Thanks!

Answer 1

Using dummy data:

# dummy dataframe
x = np.linspace(0,2*np.pi, 100)

df= pd.DataFrame({
    'a': x,
    'b': np.cos(x),
    'c': np.sin(x), 
})

fig = plt.figure()
ax=fig.add_subplot(111)
sns.lineplot('a', 'b', data=df, ax=ax, label='b')
sns.lineplot('a', 'c', data=df, ax=ax, label='c')

ax.fill_between(df['a'], 0.5, df['b'], where=df['b']>.5)
ax.fill_between(df['a'], 0.5, df['c'], where=df['c']>.5)