熊猫：用标记绘制数据框对象？

Question

This is my pandas DataFrame.

   value  action
0      1       0
1      2       1
2      3       1
3      4       1
4      3       0
5      2       1
6      5       0

What I want to do is mark value as o if action=0 , x if action=1 .

So, the plot marker should be like this: oxxxoxo

But have no idea how to do this...

Need your helps. Thanks.

Answer 1

You can plot the filtered dataframe. Ie, you can create two dataframes, one for action 0 and one for action 1. Then plot each individually.

import pandas as pd

df = pd.DataFrame({"value":[1,2,3,4,3,2,5], "action":[0,1,1,1,0,1,0]})
df0 = df[df["action"] == 0]
df1 = df[df["action"] == 1]

ax = df.reset_index().plot(x = "index", y="value", legend=False, color="gray", zorder=0)
df0.reset_index().plot(x = "index", y="value",kind="scatter", marker="o", ax=ax)
df1.reset_index().plot(x = "index", y="value",kind="scatter",  marker="x", ax=ax)

Answer 2

Consider the following approach:

plt.plot(df.index, df.value, '-X', markevery=df.index[df.action==1].tolist())
plt.plot(df.index, df.value, '-o', markevery=df.index[df.action==0].tolist())

Result:

alternative solution:

plt.plot(df.index, df.value, '-')
plt.scatter(df.index[df.action==0], df.loc[df.action==0, 'value'],
            marker='o', s=100, c='green')
plt.scatter(df.index[df.action==1], df.loc[df.action==1, 'value'], 
            marker='x', s=100, c='red')

Result: