如何使用matplotlib将txt文件中的det unix时间值转换为日期值？

Question

I basically want to convert the unix time values I have in the first row of my text file named 'EKTE9' to date. I think using the datetime library is the way to go, but I don't know how to implement that in my code. Some answers would be appreciated.

import matplotlib.pyplot as plt
import csv

x = []
y = []

with open('EKTE9.txt','r') as csvfile:
    plots = csv.reader(csvfile, delimiter=',')
    for row in plots:
        x.append(int(row[0]))
        y.append(float(row[3]))

plt.plot(x,y, label='Temperatur')
plt.xlabel('Tid')
plt.ylabel('Temperatur')
plt.title('Grafen viser temperatur under forsøket\n')
plt.legend()
plt.show()

Here are some values from the EKTE9.txt file:

1554058225,0.80,2.90,13.60,27.20
1554058525,0.30,0.80,9.60,26.70

The values goes on for about 200 lines

Answer 1

You would first create a datetime object using datetime.fromtimestamp() . This can then be converted to a matplotlib number using date2num() . Finally, you should use a DateFormatter() to help with displaying the x-axis.

import matplotlib
import matplotlib.pyplot as plt
from datetime import datetime
import csv

x = []
y = []

with open('EKTE9.txt', 'r', newline='') as csvfile:
    plots = csv.reader(csvfile, delimiter=',')

    for row in plots:
        x.append(matplotlib.dates.date2num(datetime.fromtimestamp(int(row[0]))))
        y.append(float(row[3]))

hfmt = matplotlib.dates.DateFormatter('%d\n%H:%M')
plt.plot(x,y, label='Temperatur')
plt.gca().xaxis.set_major_formatter(hfmt)
plt.xlabel('Tid')
plt.ylabel('Temperatur')
plt.title('Grafen viser temperatur under forsøket\n')
plt.legend()
plt.show()

This would then show your two values as follows:

Answer 2

That did the job. Thank you very much Martin Evans. Fina code:

import matplotlib
import matplotlib.pyplot as plt
from datetime import datetime
import csv

x = []
y = []

with open('EKTE9.txt','r') as csvfile:
     plots = csv.reader(csvfile, delimiter=',')

     for row in plots:
        x.append(matplotlib.dates.date2num(datetime.fromtimestamp(int(row[0]))))
        y.append(float(row[3]))

hfmt = matplotlib.dates.DateFormatter('%d\n%H:%M')
plt.plot(x,y, label='Temperatur')
plt.gca().xaxis.set_major_formatter(hfmt)
plt.xlabel('Tid')
plt.ylabel('Temperatur')
plt.title('Grafen viser temperatur under forsøket\n')
plt.legend()
plt.show()