蘇嘉瑞LIST清單DICT字典RANDOM模組
#註解蘇嘉瑞學過python
import random
x =[ i for i in range(10)]
print('產生清單',x)
y={}
for i in x:
y[i]=random.random()
print(y)
for i in y:
print(i,y[i])
馬可維茲風險平均數平面
6月 12, 2025 https://drive.google.com/file/d/1DEfDy4-l1ikSiOpCNR6SZR7iRB5fvIbt/view?usp=drive_link 6/20程式碼 import csv #輸入csv套件comma separated value f = open('200201to202505.csv','r', encoding="utf-8")#打開下載的檔案SPY.CSV,模式是r讀取, csvreader = csv.reader(f) #將檔案讀入變數csvreader header, rows = list(), list() #宣告空白串列(陣列,清單) firms = set() #建構集合 header = next(csvreader) #串列header儲存檔案第一列 for record in csvreader: #檔案紀錄，逐列row檢視 rows.append(record) #第i筆附加append於rows串列成為rows[i] firms.add(record[0]) #row[0]公司名稱 f.close() #關閉檔案 months = dict() for year in range(2007,2026): months[year]=[str(year*100+month) for month in range(1,13)] count, sum, sumSq, mean, stdev = dict(), dict(), dict(), dict(), dict() for firm in firms: for year in range(2007, 2026): t = (firm, year) #元組(公司,年) count[t] = 0 sum[t] = 0.0 su...
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