如何用Python繪製區域圖？

首先，這是我們的資料：

import pandas as pd

data = pd.read_excel("勞工保險基金每月經營概況.xlsx")

data["基金運用餘額（億元）"] = (data["基金運用餘額（金額）"]/100000000).astype("int")

data["基金收益數（億元）"] = (data["基金收益數（金額）"]/100000000).astype("int")

data["年月"] = list(map(lambda x: str(x)[0:4]+"\n"+str(x)[5:7],data["月別"]))

data.drop(columns=["月別","基金運用餘額（金額）","基金收益數（金額）"],inplace=True)

利用迴圈計算累積收益：

maonylist = []

x = 0
for i in data["基金收益數（億元）"]:
    x = i + x
    maonylist.append(x)

data["累積基金收益數（億元）"] = pd.Series(maonylist)

整理好資料，我們就可以來繪圖了：

import matplotlib

#設定中文字型​
matplotlib.rc("font",family="Microsoft Yahei")

from matplotlib import pyplot as plt

#設定圖表大小​
plt.figure(figsize=(12,6))

#設定子圖位置​
ax = plt.subplot2grid((1,1),(0,0))
​
#設定x、y資料​
ax_x = data["年月"]
ax_y1 = data["基金收益數（億元）"]
ax_y2 = data["累積基金收益數（億元）"]
ax_y3 = data["基金運用餘額（億元）"]

#區域圖（fill_between(x,y1,y2)）:填充y1、y2間的面積​
ax.fill_between(ax_x,ax_y3,0,label="基金運用餘額",color="darkgray",alpha=0.5)
ax.fill_between(ax_x,ax_y2,0,label="累積基金收益數",color="green",alpha=0.5)
ax.fill_between(ax_x,ax_y1,0,label="基金收益數",color="lightgreen",alpha=0.5)

#設定y軸參數​
ax.set_ylim(0,10000)
ax.set_yticks([2500,5000,7500,10000,12500])
ax.set_yticklabels(["2千\n500億","5千億","7千\n500億","1兆","1兆\n2500億"])

#設定圖例​
ax.legend(loc="upper left")

#設定文字​
for a,b,c,d in zip(ax_x,ax_y1,ax_y2,ax_y3):
    ax.text(a,b+150,str(b)+"億",horizontalalignment="center",color="lightgreen")
    ax.text(a,c+150,str(c)+"億",horizontalalignment="center",color="green")
    ax.text(a,d+150,str(d)+"億",horizontalalignment="center",color="darkgray")

#設定標題​
ax.set_title("2023年3月至2024年3月\n勞工保險基金每月經營概況")