pandas 更改 Matplotlib 图表 X 轴上的顺序
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Change Order on X-Axis for Matplotlib chart
提问by user8659376
I created a chart in matplotlib using python and the x-axis is the days of the week (Mon-Sun). When the data was plotted though, the x-axis is not arranged Mon-Sun.
我使用 python 在 matplotlib 中创建了一个图表，x 轴是一周中的几天（周一至周日）。但是，绘制数据时，x 轴并未排列在周一至周日。
Is there way I can re-order the x-axis to have it be formatted this way?
有什么方法可以重新排序 x 轴以使其格式化？
or is there a way I can re-order the dataset? It is a csv file that is being read using the panda dataframe
或者有什么方法可以重新排序数据集？这是一个使用Pandas数据框读取的 csv 文件
Example Data: (lives in csv: './data/Days_Summary.csv')
示例数据：（存在于 csv 中：'./data/Days_Summary.csv'）
Day Value
Monday 56
Tuesday 23
Wednesday 34
Thursday 56
Friday 58
Saturday 70
Sunday 43
Code:
代码：
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
df=pd.read_csv('./data/Days_Summary.csv')
days_values=df.groupby(['day'])['day'].count().plot(kind='bar')
plt.xlabel('Day')
plt.ylabel('Values')
plt.show()
回答by andrew_reece
Use .locto set the day order:
使用.loc设置天阶：
field = "Day"
day_order = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]
ax = df.set_index(field).loc[day_order].plot(kind="bar", legend=False)
ax.set_ylabel("Value")
Note: Using groupby()and count()will not give you the values in the Valuefield, but will instead count the number of rows in each group. In this case, you'll just get a count of 1 for each day. Hence this answer assumes that
you actually want to plot the values in Valuefor each day.
注意：使用groupby()和count()不会为您提供Value字段中的值，而是会计算每组中的行数。在这种情况下，您每天只会得到 1 的计数。因此，这个答案假设您实际上想要绘制Value每天的值。
