matplotlib plot datetime in pandas DataFrame

Question

I have a pandas DataFrame that looks like this training.head()

The DataFrame has been sorted by date. I'd like to make a scatterplot where the date of the campaign is on the x axis and the rate of success is on the y axis. I was able to get a line graph by using training.plot(x='date',y='rate'). However, when I changed that to training.plot(kind='scatter',x='date',y='rate') I get an error: KeyError: u'no item named date'

Why does my index column go away when I try to make a scatterplot? Also, I bet I need to do something with that date field so that it doesn't get treated like a simple string, don't I?

Extra credit, what would I do if I wanted each of the account numbers to plot with a different color?

Answer 1

If I remember correctly, the plotting code only considers numeric columns. Internally it selects just the numeric columns, so that's why you get the key error.

What's the dtype of date? If it's a datetime64, you can recast it as an np.int64:

df['date_int'] = df.date.astype(np.int64)

And then you're plot.

For the color part, make a dictionary of {account number: color}. For example:

color_d = {1: 'k', 2: 'b', 3: 'r'}

Then when you plot:

training.plot(kind='scatter',x='date',y='rate', color=df.account.map(color_d))

Answer 2

I've found it simpler to change the style of a line chart to not include the connecting lines:

cb_df.plot(figsize=(16, 6), style='o')