解說：
https://matters.news/@makzan/299154
最終代碼：
import numpy as np
import pandas as pd
files = [ "中文", "英文", "數學", "物理", "化學" ]
# The first file
topic = files[0]
df = pd.read_excel(topic + ".xlsx")
df = df.rename(columns={ "總成績": topic })
df = df[["學生編號", topic]]
# All other files
for topic in files[1:]:
df2 = pd.read_excel(topic + ".xlsx")
df2 = df2.rename(columns={
"總成績": topic
})
df2 = df2[["學生編號", topic]]
df = df.merge(df2, on="學生編號")
df = df.round()
df["學生編號"] = df["學生編號"].astype(int)
df = df.set_index("學生編號")
df.to_excel("result.xlsx")
