蠟燭線是股票分析中常用的一種技術指標，通過蠟燭線圖可以直觀地看出股票價格的變化情況。在Python中，我們可以使用matplotlib庫來實現畫蠟燭線。

import matplotlib.pyplot as plt
from matplotlib.dates import DateFormatter, WeekdayLocator, DayLocator, MONDAY
from mpl_finance import candlestick_ohlc
import pandas as pd
# 讀入數據，這里我們使用Google的股票數據
goog = pd.read_csv('https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=GOOG&apikey=demo&datatype=csv')
# 處理日期數據，轉化為數字
goog['date'] = pd.to_datetime(goog['timestamp'])
goog['date'] = goog['date'].apply(lambda x: DateFormatter('%Y-%m-%d')(x))
goog['date'] = pd.to_datetime(goog['date'])
goog['date'] = goog['date'].apply(lambda x: x.toordinal())
# 繪制蠟燭圖
mondays = WeekdayLocator(MONDAY)
alldays = DayLocator()
weekFormatter = DateFormatter('%b %d')
dayFormatter = DateFormatter('%d')
fig, ax = plt.subplots()
fig.subplots_adjust(bottom=0.2)
ax.xaxis.set_major_locator(mondays)
ax.xaxis.set_minor_locator(alldays)
ax.xaxis.set_major_formatter(weekFormatter)
candlestick_ohlc(ax, zip(goog['date'], goog['open'], goog['high'], goog['low'], goog['close']), width=0.6)
ax.xaxis_date()
ax.autoscale_view()
plt.setp(plt.gca().get_xticklabels(), rotation=45, ha='right')
plt.show()

代碼中使用了pandas庫來讀取和處理數據，然后使用matplotlib的candlestick_ohlc()函數繪制蠟燭圖。其中，我們將日期轉化為數字，并使用WeekdayLocator和DayLocator設置X軸的坐標。最后使用plt.show()函數顯示圖形。