python - 如何突出情节中的周末？

Question

对于简单的时间序列:

import pandas as pd
df = pd.DataFrame({'dt':['2020-01-01', '2020-01-02', '2020-01-04', '2020-01-05', '2020-01-06'], 'foo':[1,2, 4,5,6]})
df['dt'] = pd.to_datetime(df.dt)
df['dt_label']= df['dt'].dt.strftime('%Y-%m-%d %a')
df = df.set_index('dt')
#display(df)
df['foo'].plot()
x =plt.xticks(ticks=df.reset_index().dt.values, labels=df.dt_label, rotation=90, horizontalalignment='right')

如何突出显示周末的 x 轴标签？

编辑

Pandas Plots: Separate color for weekends, pretty printing times on x axis

建议:

def highlight_weekends(ax, timeseries):
    d = timeseries.dt
    ranges = timeseries[d.dayofweek >= 5].groupby(d.year * 100 + d.weekofyear).agg(['min', 'max'])
    for i, tmin, tmax in ranges.itertuples():
        ax.axvspan(tmin, tmax, facecolor='orange', edgecolor='none', alpha=0.1)

但应用它

highlight_weekends(ax, df.reset_index().dt)

不会改变剧情

Answer 1

我对您的示例数据进行了一些扩展，以便我们可以确保我们可以突出显示多个周末实例。

在此解决方案中，我创建了一个列 'weekend' ，这是一列 bool 值，指示相应的日期是否是周末。

然后我们循环这些值并调用 ax.axvspan

import pandas as pd
import matplotlib.pyplot as plt

# Add a couple of extra dates to sample data
df = pd.DataFrame({'dt': ['2020-01-01',
                          '2020-01-02',
                          '2020-01-04',
                          '2020-01-05',
                          '2020-01-06',
                          '2020-01-07',
                          '2020-01-09',
                          '2020-01-10',
                          '2020-01-11',
                          '2020-01-12']})
# Fill in corresponding observations
df['foo'] = range(df.shape[0])

df['dt'] = pd.to_datetime(df.dt)

df['dt_label']= df['dt'].dt.strftime('%Y-%m-%d %a')

df = df.set_index('dt')

ax = df['foo'].plot()
plt.xticks(ticks=df.reset_index().dt.values, 
           labels=df.dt_label,
           rotation=90,
           horizontalalignment='right')

# Create an extra column which highlights whether or not a date occurs at the weekend
df['weekend'] = df['dt_label'].apply(lambda x: x.endswith(('Sat', 'Sun')))

# Loop over weekend pairs (Saturdays and Sundays), and highlight
for i in range(df['weekend'].sum() // 2):
    ax.axvspan(df[df['weekend']].index[2*i],
               df[df['weekend']].index[2*i+1],
               alpha=0.5)