Can'；t让legend在Python图形上工作

我需要在右上角有一个图例来详细说明“天线1”和“天线2”，但如果没有错误，我无法让任何东西正常工作

这是我的密码：

import matplotlib
import matplotlib.pyplot as plt
import matplotlib.animation as animation

from datetime import datetime, timedelta
import collections
import csv

offset = -7.4954
slope = 0.9548

def plot(ax, data, colour, width):
    if data:
        last_dt = data[0][0]
        gap = timedelta(seconds=20)

        x = []
        y = []

        # Plot groups of data not more than 60 seconds apart
        for dt, ten in data:
            if dt <= last_dt + gap:
                x.append(dt)
                y.append(ten)
            else:
                ax.plot(matplotlib.dates.date2num(x), y, colour, linewidth=width)
                x = [dt]
                y = [ten]

            last_dt = dt

        ax.plot(matplotlib.dates.date2num(x), y, colour, linewidth=width)


def animate(i, fig, ax):
    # Read in the CSV file
    data = collections.defaultdict(list)
    fields = ["TimeStamp", "ReadCount", "Antenna", "Protocol", "RSSI", "EPC", "Temp", "Ten", "Powr", "Unpowr", "Inf"]

    with open('SensorLog.csv') as f_input:
        csv_input = csv.DictReader(f_input, skipinitialspace=True, fieldnames=fields)
        header = next(csv_input)

        # Separate the rows based on the Antenna field
        for row in csv_input:
            try:
                data[row['Antenna']].append(
                    [datetime.strptime(row['TimeStamp'], '%m/%d/%Y %H:%M:%S.%f'), 
                    int(float(row['Ten']) * float(slope) + float(offset))])
            except:
                pass

    # Drop any data points more than 5 mins older than the last entry

    latest_dt = data[row['Antenna']][-1][0]     # Last entry
    not_before = latest_dt - timedelta(minutes=2)

    for antenna, entries in data.items():
        data[antenna] = [[dt, count] for dt, count in entries if dt >= not_before]

    # Redraw existing axis
    ax.clear()

    ax.spines['bottom'].set_color("#5998ff")
    ax.spines['top'].set_color("#5998ff")
    ax.spines['left'].set_color("#5998ff")
    ax.spines['right'].set_color("#5998ff")

    hfmt = matplotlib.dates.DateFormatter('%m/%d/%Y\n%I:%M:%S %p')
    ax.xaxis.set_major_formatter(hfmt)
    fig.autofmt_xdate()

    plot(ax, data['1'], 'c', 2)     # Antenna 1
    plot(ax, data['2'], 'r', 2)     # Antenna 2

    ax.grid(True, color='w')
    plt.ylabel('Tension (lb)', color='w', fontsize=20)
    plt.title('Spiral 1 Tension', color='w', fontsize=26)

    ax.tick_params(axis='y', colors='w')
    ax.tick_params(axis='x', colors='w')

    ax.set_ylim([30,60])

fig = plt.figure(facecolor='#07000d')
ax = fig.add_subplot(111, axisbg='#07000d')

ani = animation.FuncAnimation(fig, animate, fargs=(fig, ax), interval=1000)
plt.show()

然后加上

plt.legend()

以前

plt.show()

然而，这并没有奏效

有什么帮助吗

plt.show()