如何从列表中获取一个值，然后将其用于基本数学方程式？

Question

我正在尝试从 api 提供的列表中获取浮点值。当我打印它时，我能够让它看起来像一个浮点值，但我不认为它是一个真实的数字，因为我不能在我的数学方程式中使用它。还有其他函数可以获取 trailTrigger 和 stopLoss，但我很高兴它们可以工作。我只是无法让 lastTradePrice 成为我可以使用的浮点数。

    # Call My last trade from Coinbase
def coinBaseMyLastTrade():
    global lastTradePrice
    global lastTradeSize
    global lastTradeFee
    global lastTradeSide
    global lastTradeSettled
    myLastTrade = requests.get(api_url + 'fills?product_id=BTC-USDC&limit=1', auth=auth)
    lastTradeList = myLastTrade.json()
    lastTradePrice = [float(lastTradeList_item['price']) for lastTradeList_item in lastTradeList]
    lastTradeSize = [float(lastTradeList_item['size']) for lastTradeList_item in lastTradeList]
    lastTradeFee = [float(lastTradeList_item['fee']) for lastTradeList_item in lastTradeList]
    lastTradeSide = [str(lastTradeList_item['side']) for lastTradeList_item in lastTradeList]
    lastTradeSettled = [lastTradeList_item['settled'] for lastTradeList_item in lastTradeList]
    print 'My Last Trade Price =',lastTradePrice
    print 'My Last Trade Size =',lastTradeSize
    print 'My Last Trade Fee =',lastTradeFee
    print 'My Last Trade Side =',lastTradeSide
    print 'My Last Trade Settled =',lastTradeSettled
    return

# Work out the value to use to trigger the trail loop
def calculateTrailTriggerValue():
    global triggerValue
    global stoplossValue
    if "buy" in lastTradeSide:
        triggerValue = lastTradePrice * ((100+trailTrigger)/100)
        stoplossValue = lastTradePrice * ((100-stoploss)/100)
    elif "sell" in lastTradeSide:
        triggerValue = lastTradePrice * ((100-trailTrigger)/100)
        stoplossValue = lastTradePrice * ((100+stoploss)/100)
    print 'Trail Trigger $=',triggerValue
    print 'Stop Loss $=',stoplossValue
    return

当我运行代码时，我得到了错误

triggerValue = lastTradePrice * ((100-trailTrigger)/100)
TypeError: can't multiply sequence by non-int of type 'float'

这很奇怪，因为我在不同的列表上使用了这段代码，我能够使用这些值，但它不适用于我需要帮助的代码

# Call 24hour stats
def coinBasePastDayStats():
    dayStats = requests.get('https://api.pro.coinbase.com/products/BTC-USDC/stats')
    dayHigh = float(dayStats.json()['high'])
    dayLow = float(dayStats.json()['low'])
    dayChange = dayHigh - dayLow
    global dayChangePercent
    dayChangePercent = (dayChange / dayHigh) * 100
    print 'Last 24hr High =', dayHigh
    print 'Last 24hr Low =', dayLow
    print 'Last 24hr Change =', dayChange
    print 'Last 24hr Change Percent =', {:.2f}".format(dayChangePercent),'%'
    return

如果有人能帮我列出一个列表值并将其用于基本数学方程式，我将不胜感激。干杯

Answer 1

如果你想像这样乘以整个列表，我建议使用 numpy 数组

import numpy as np
arr = np.array([ i for i in range(10)])
arr *= 2

Answer 2

看来您的方向是正确的。但正如其他人所说，您正在对列表本身进行操作，python 不支持。

如果不使用 numpy，您必须遍历列表并依次对每个值执行操作。

如何从列表中获取一个值，然后将其用于基本数学方程式？

How can I take a value from a list and then use it in a basic math equation?

python

list

multiplication