无法更改 matplotlib 上绘制线条的颜色

Question

在此处引用此 SO 帖子：Matplotlib set_color_cycle versus set_prop_cycle

但我无法将所有 20 条线的颜色设置为不同，图表图片如下：

这是我的代码：

import matplotlib as mpl
import matplotlib.pyplot as plt
import seaborn as sns
import numpy as np
import pandas as pd
from cycler import cycler


df = pd.read_csv(r'data.csv', index_col="Date", parse_dates=True)


df.rolling(window=30).max()[30:].head(20)
ax = df.plot()
ax.set(title='Qingdao Port', ylabel='Monthly Average Prices')
ax.set_prop_cycle('color',plt.cm.jet(np.linspace(0,1,20)))
plt.show()

请帮帮我！

Answer 1

用户 DavidG 帮助我解决了这个问题，更新后的代码将包含在此处以供将来参考：

import matplotlib as mpl
import matplotlib.pyplot as plt
import seaborn as sns
import numpy as np
import pandas as pd  
from cycler import cycler

fig, ax = plt.subplots()

ax.set_prop_cycle('color',plt.cm.tab20(np.linspace(0,1,20)))

df = pd.read_csv(r'data.csv', index_col="Date", parse_dates=True)


df.rolling(window=30).max()[30:].head(20)
df.plot(ax=ax)
ax.set(title='Qingdao Port', ylabel='Monthly Average Prices')
plt.show()