Question

我一直在试图找出如何绘制这些数据，但无法找出我的错误：

 Month      Year       Sales
January     2020       43
feburary    2020       23
March       2020       13
April       2020       11
May         2020        7
June        2020        2  
July        2020        1
August      2020        2
September   2020        22 
October     2020       11
November    2020        6
December    2020        3
January     2019        3
feburary    2019        11
March       2019        65 
April       2019        22
May         2019        33
June        2019        88
July        2019        44
August      2019        12
September   2019        32
October     2019        54
November    2019        76
December    2019        23
January     2018        12
feburary    2018        32
March       2018        234
April       2018        2432
May         2018        432
June        2018        324   
July        2018        12
August      2018        324
September   2018        89
October     2018        6
November    2018        46
December    2018        765

我尝试了以下

y = df["sales"]
x = df["Month"]

plt.plot(x,y)
plt.show()

下面给出了以下图表（确切的值随此处发布的数据值的变化而有所不同）：

我该如何纠正它，以使我的地块在每次12月都中断，并为另一年画一条新线？

Answer 1

如果您的熊猫DataFrame如下所示：

    year      month   sales
0   2020    January    43.0
1   2020   feburary    23.0
2   2020      March    13.0
3   2020      April    11.0
4   2020        May     7.0
5   2020       June     2.0
6   2020       July     1.0
7   2020     August     2.0
8   2020  September    22.0
9   2020    October    11.0
10  2020   November     6.0
11  2020   December     3.0
12  2019    January     3.0
13  2019   feburary    11.0
14  2019      March    65.0
15  2019      April    22.0
16  2019        May    33.0
17  2019       June    88.0
18  2019       July    44.0
19  2019     August    12.0
20  2019  September    32.0
21  2019    October    54.0
22  2019   November    76.0
23  2019   December    23.0
24  2018    January    12.0
25  2018   feburary    32.0
26  2018      March   234.0
27  2018      April  2432.0
28  2018        May   432.0
29  2018       June   324.0
30  2018       July    12.0
31  2018     August   324.0
32  2018  September    89.0
33  2018    October     6.0
34  2018   November    46.0
35  2018   December   765.0

我们可以使用df.groupby('year')来生成您想要的解析类型：

fig, ax = plt.subplots()
ax.set_xticklabels(df['month'].unique(), rotation=90)

for name, group in df.groupby('year'):
    ax.plot(group['month'], group['sales'], label=name)

ax.legend()
plt.tight_layout()
plt.show()

Answer 2

只需将图添加到同一图形即可：

from matplotlib import pyplot as plt
import pandas as pd

data = pd.read_csv('year_data.csv')

for year in data['Year'].unique():
    plt.plot(data[data['Year']==year]['Month'], data[data['Year']==year]['Sales'])

plt.xticks(rotation=90)
plt.show()

上面的代码给出了类似的内容：

Answer 3

尝试将列转换为DataTime数据类型：

$column-gap

您现在应该可以根据自己的日期进行绘图了。

Answer 4

您当前的绘图正在汇总同一图表中的所有年份，因此当您到达年底时，它实际上会“循环”。

您可以在12个月的时间段内分割数据框，然后将其实际绘制在同一matplotlib子图上，作为不同的行：

import pandas as pd
import matplotlib.pyplot as plt

######################
## DATA PREPARATION ##
######################

sales20 = df.loc[df['Year'] == 2020, 'Sales']
sales19 = df.loc[df['Year'] == 2019, 'Sales']


##############
## PLOTTING ##
##############

# Create a new figure
fig = plt.figure()
# Add a subplot to the figure
ax = fig.add_subplot()
# Add to the subplot two line plots labeled accordingly
ax.plot(df["Month"], sales20, label='2020')
ax.plot(df["Month"], sales19, label='2019')
# Add handy legend
ax.legend(loc='best')
# Finger crossed and show the graph
plt.show()

我必须承认这是一个快速而肮脏的解决方案...

一种更优雅的方法是将数据帧转换为使用datetime索引进行索引，请查看Pandas docs on the matter

绘制每月重复数据python

4 个答案: