Plot datetime.date pandas

Question

I created a pandas dataframe from some value counts on particular calendar dates. Here is how I did it:

time_series = pd.DataFrame(df['Operation Date'].value_counts().reset_index())
time_series.columns = ['date', 'count']

Basically, it is two columns, the first "date" is a column with datetime.date objects and the second column, "count" are simply integer values.

Now, I'd like to plot a scatter or a KDE to represent the value changes over the calendar days, but how?

I looked at the dataframe and it all looks in order and exactly as I describe above. But when I try:

time_series.plot(kind='kde')
plt.show()

I get a plot where the x-axis is from -50 to 150 as if it is parsing the datetime.date objects as integers somehow. Also, it is yielding two identical plots rather than just one.

Any idea how I can plot them and see the calendars day along the x-axis?

Solution

you sure you got datetime? i just tried this and it worked fine:

df =    date    count
7   2012-06-11 16:51:32 1.0
3   2012-09-28 08:05:14 12.0
19  2012-10-01 18:01:47 4.0
2   2012-10-03 15:18:23 29.0
6   2012-12-22 19:50:43 4.0
1   2013-02-19 19:54:03 28.0
9   2013-02-28 16:08:40 17.0
12  2013-03-12 08:42:55 6.0
4   2013-04-04 05:27:27 6.0
17  2013-04-18 09:40:37 29.0
11  2013-05-17 16:34:51 22.0
5   2013-07-07 14:32:59 16.0
14  2013-10-22 06:56:29 13.0
13  2014-01-16 23:08:46 20.0
15  2014-02-25 00:49:26 10.0
18  2014-03-19 15:58:38 25.0
0   2014-03-31 05:53:28 16.0
16  2014-04-01 09:59:32 27.0
8   2014-04-27 12:07:41 17.0
10  2014-09-20 04:42:39 21.0

df = df.sort_values('date', ascending=True)
plt.plot(df['date'], df['count'])
plt.xticks(rotation='vertical')

EDIT:

if you want a scatter plot you can:

plt.plot(df['date'], df['count'], '*')
plt.xticks(rotation='vertical')

Comments

[guy]

Thanks that worked for some weird reason. Also, I removed the backslashes in your 2nd line of code, not sure why you included it.....thanks!

[SPS]

I'm not sure if it's too late, but I'd want to know 'plt' stays for what?

[epattaro]

import matplotlib.pyplot as plt

[msarafzadeh]

This is very helpful and straight to the point. A very universal answer.

[Christa]

Is there a way to add color to this plot using another variable?

[epattaro]

Hi christina, there is the color argument, see this post: stackoverflow.com/questions/22408237/named-colors-in-matplot‌​lib , its also possible to plot multiple graphs in the same figure, each with its own color. For that, just run the plot command N times, each with its data and color parameters.