如何将熊猫系列绘制为水平线？

Question

I have the following code:

import pandas as pd
import matplotlib.pyplot as plt


df = pd.read_csv("data.csv")

short_run = df["High"][df["Volume"] >= df["Volume"].quantile(0.999)][1:22]

short_run.plot()
plt.show()

Output of short_run :

1012     0.000189
1013     0.000167
11696    0.000096
25019    0.000075
25020    0.000076
25071    0.000077
25072    0.000078
25073    0.000081
25079    0.000085
25080    0.000089
25081    0.000090
25083    0.000095
25084    0.000099
25085    0.000117
25086    0.000106
25087    0.000103
25088    0.000100
25089    0.000090
25090    0.000092
25092    0.000089
25093    0.000086

Which outputs the following diagram:

I was wondering how instead of getting a line plot I could instead get a bunch of horizontal lines (which intersect the y-axis based on the values of short_run ). In other words how can I turn the previous diagram into this one:

(PS: I don't need the red line, I just included to make it easier to understand)

Thank you very much for your help

Answer 1

You failed to provide a Minimal, Complete, and Verifiable example . Since I do not have your DataFrame, I can tell you an indirect solution.

The idea is to get the axis instance returned by the df.plot and then get the y-data. Then, loop over the values and plot a horizontal line at each of them. To hide your actual red line, the easiest thing to my mind is to use white color again since you did not provide any reproducible code

ax = df.plot(color='white')
line = ax.lines[0]
for y in line.get_ydata():
    plt.axhline(y)

Alternatively, assuming your y-values are in a variable y_val , you do not need to first plot the DataFrame. You can directly use matplotlib as

import matplotlib.pyplot as plt

for y in y_val:
    plt.axhline(y)

plt.show()