python - 类型错误 : 'float' object is not iterable trying to annotate an arrow from a list

Question

我正在尝试注释从列表列表的 XY 坐标派生的箭头。我可以让绘图在某个点显示注释，但当我尝试在两个 XY 坐标之间添加箭头时，出现类型错误:'float'对象不可迭代。

代码如下:

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

visuals = [[],[],[],[],[]]

with open('XY_Data.csv') as csvfile :
    readCSV = csv.reader(csvfile, delimiter=',')
    n=0
    for row in readCSV :
        if n == 0 :
            n+=1
            continue
        visuals[0].append(list(map(float, row[3:43][::2]))) #X-Coordinate of 21 subjects
        visuals[1].append(list(map(float, row[2:42][::2]))) #Y-Coordinate of 21 subjects
        visuals[3].append([float(row[44]),float(row[46])]) #X-Coordinate of the subject I want to display the arrow between
        visuals[4].append([float(row[45]),float(row[47])]) #Y-Coordinate of the subject I want to display the arrow between

fig, ax = plt.subplots(figsize = (8,8))
plt.grid(False)

scatter = ax.scatter(visuals[0][0], visuals[1][0], c=['blue'], alpha = 0.7, s = 20, edgecolor = 'black', zorder = 1) #Scatter plot (21 subjects)
scatterO = ax.scatter(visuals[3][0], visuals[4][0], c=['black'], marker = 'o', alpha = 0.7, s = 25, edgecolor = 'black', zorder = 2) #Scatter plot (intended subject)

annotation = ax.annotate('Player 1', xy=(visuals[0][0][0],visuals[1][0][0]), fontsize = 8) #This annotation is displayed at the XY coordinate of the subject in the first column of the dataset
arrow = ax.annotate('', xy = (visuals[3][0][0]), xytext = (visuals[4][0][0]), arrowprops = {'arrowstyle': "<->"}) #This function returns an error

我做了什么不同的事情？

Answer 1

您没有指出此错误发生在哪里。但我猜它在最后一行:

arrow = ax.annotate('', xy = (visuals[3][0][0]), xytext = (visuals[4][0][0]), arrowprops = {'arrowstyle': "<->"}) #This function returns an error

来自 doc , xy 参数是可迭代的，但在您的代码中，xy 只有 1 个浮点值，您应该尝试如下操作:

xy=(视觉效果[3][0][0],视觉效果[4][0][0]), xytext = (视觉效果[3][0][1],视觉效果[4] [0][1])

而不是

xy = (视觉效果[3][0][0])