如何将Matplotlib中的标记替换为与线条同色的足球图标？

要把图表里的圆形散点换成和线条同色的足球图标，有两种简单的实现方式：

方法一：用足球Emoji快速搞定（无需额外资源） #

直接用系统支持的足球emoji代替散点，代码改动最小，还能自动匹配线条颜色：

把你原代码里的plt.scatter()部分删掉，换成下面的代码：

# 获取客队线条的默认颜色
away_color = ax.lines[0].get_color()

# 给每个客队进球点放足球emoji
for x, y in zip(a_goal['minute'], a_goal['a_cum']):
    ax.text(x, y, '⚽', fontsize=14, color=away_color, ha='center', va='center')

# 给每个主队进球点放红色足球emoji
for x, y in zip(h_goal['minute'], h_goal['h_cum']):
    ax.text(x, y, '⚽', fontsize=14, color='red', ha='center', va='center')

完整代码如下：

import matplotlib.pyplot as plt

fig, ax = plt.subplots(figsize=(12,6))

ax.step(x = a_df['minute'], y = a_df['a_cum'], where = 'post', label= ateam, linewidth=2)
ax.step(x = h_df['minute'], y = h_df['h_cum'], where = 'post', color ='red', label= hteam,linewidth=2)  

# 替换散点为足球emoji
away_color = ax.lines[0].get_color()
for x, y in zip(a_goal['minute'], a_goal['a_cum']):
    ax.text(x, y, '⚽', fontsize=14, color=away_color, ha='center', va='center')

for x, y in zip(h_goal['minute'], h_goal['h_cum']):
    ax.text(x, y, '⚽', fontsize=14, color='red', ha='center', va='center')

plt.xticks([0,15,30,45,60,75,90])
plt.yticks([0, 0.5, 1, 1.5, 2, 2.5, 3])
plt.grid()

ax.title.set_text('The Expected Goals(xG) Chart Final Champions League 2010/2011')
plt.ylabel("Expected Goals (xG)")
plt.xlabel("Minutes")
ax.legend()
plt.show()

方法二：用自定义足球图片（更逼真） #

如果想要更真实的足球样式，可以用一张透明背景的足球PNG图片，给图标染色后放到对应位置：

1. 先准备一张透明背景的足球PNG（比如命名为football.png）
2. 替换原代码的散点部分为以下代码：

import matplotlib.pyplot as plt
from matplotlib.offsetbox import OffsetImage, AnnotationBbox
from PIL import Image
from matplotlib.colors import to_rgb

fig, ax = plt.subplots(figsize=(12,6))

ax.step(x = a_df['minute'], y = a_df['a_cum'], where = 'post', label= ateam, linewidth=2)
ax.step(x = h_df['minute'], y = h_df['h_cum'], where = 'post', color ='red', label= hteam,linewidth=2)  

# 定义给足球图标染色并添加到图表的函数
def add_colored_football(ax, x, y, img_path, target_color, zoom=0.05):
    # 加载透明背景的足球图片
    img = Image.open(img_path).convert("RGBA")
    # 把图标颜色转为目标线条颜色
    rgb_color = to_rgb(target_color)
    data = img.getdata()
    new_data = []
    for r, g, b, alpha in data:
        if alpha > 0:
            # 替换颜色，保留透明度
            new_data.append((int(rgb_color[0]*255), int(rgb_color[1]*255), int(rgb_color[2]*255), alpha))
        else:
            new_data.append((r, g, b, alpha))
    img.putdata(new_data)
    
    # 创建图标并定位到进球点
    im = OffsetImage(img, zoom=zoom)
    ab = AnnotationBbox(im, (x, y), frameon=False, pad=0.0)
    ax.add_artist(ab)

# 添加客队进球图标
away_color = ax.lines[0].get_color()
for x, y in zip(a_goal['minute'], a_goal['a_cum']):
    add_colored_football(ax, x, y, "football.png", away_color)

# 添加主队进球图标
for x, y in zip(h_goal['minute'], h_goal['h_cum']):
    add_colored_football(ax, x, y, "football.png", "red")

plt.xticks([0,15,30,45,60,75,90])
plt.yticks([0, 0.5, 1, 1.5, 2, 2.5, 3])
plt.grid()

ax.title.set_text('The Expected Goals(xG) Chart Final Champions League 2010/2011')
plt.ylabel("Expected Goals (xG)")
plt.xlabel("Minutes")
ax.legend()
plt.show()

内容的提问来源于stack exchange，提问作者Antonius Yoga Krisanto