Question

所以我目前正在学习如何使用numpy，pandas等分析python中的财务数据......我开始使用一个小脚本，希望通过价格变化对某些选定的股票进行排名两个选定的日期之间。我的第一个剧本是：

import numpy as np
import pandas as pd
from pandas_datareader import data as web
from pandas import Series, DataFrame
import datetime
from operator import itemgetter

#Edit below for 2 dates you wish to calculate:
start = datetime.datetime(2014, 7, 15)
end = datetime.datetime(2017, 7, 25)

stocks = ('AAPL', 'GOOGL', 'YHOO', 'MSFT', 'AMZN', 'DAI')

#Getting the data:    
AAPL = web.DataReader('AAPL', 'google', start, end)
GOOGL = web.DataReader('GOOGL', 'google', start, end)
YHOO = web.DataReader('YHOO', 'google', start, end)
MSFT = web.DataReader('MSFT', 'google', start, end)
AMZN = web.DataReader('AMZN', 'google', start, end)
DAI = web.DataReader('DAI', 'google', start, end)

#Calculating the change:
AAPLkey = (AAPL.ix[start]['Close'])/(AAPL.ix[end]['Close'])
GOOGLkey = (GOOGL.ix[start]['Close'])/(GOOGL.ix[end]['Close'])
YHOOkey = (YHOO.ix[start]['Close'])/(YHOO.ix[end]['Close'])
MSFTkey = (MSFT.ix[start]['Close'])/(MSFT.ix[end]['Close'])
AMZNkey = (AMZN.ix[start]['Close'])/(AMZN.ix[end]['Close'])
DAIkey = (DAI.ix[start]['Close'])/(DAI.ix[end]['Close'])

#Formatting the output in a sorted order:
dict1 = {"AAPL" : AAPLkey, "GOOGL" : GOOGLkey, "YHOO" : YHOOkey, "MSFT" : MSFTkey, "AMZN" : AMZNkey, "DAI" : DAIkey}

out = sorted(dict1.items(), key=itemgetter(1), reverse = True)

for tick , change in out:
    print (tick,"\t", change)

我现在显然希望缩短这一点，这是我迄今为止所做的：

import numpy as np
import pandas as pd
from pandas_datareader import data as web
from pandas import Series, DataFrame
import datetime
from operator import itemgetter

#Edit below for 2 dates you wish to calculate:
start = datetime.datetime(2014, 7, 15)
end = datetime.datetime(2017, 7, 25)

stocks = ('AAPL', 'GOOGL', 'YHOO', 'MSFT', 'AMZN', 'DAI')

for eq in stocks:
    eq = web.DataReader(eq, 'google', start, end)

for legend in eq:
    legend = (eq.ix[start]['Close'])/(eq.ix[end]['Close'])

print (legend)

计算有效但问题是这只输出列表中项目的最后一个值（DAI）。那么下一步是为了得到与我的第一个代码相同的结果呢？

Answer 1

您可以将print语句移动到循环中。

像：

for legend in eq:
    legend = (eq.loc[start]['Close'])/(eq.loc[end]['Close'])
    print(legend)

改进答案：摆脱之前循环中的标签循环和打印值：

for eq in stocks:
    df = web.DataReader(eq, 'google', start, end)
    print((df.loc[start]['Close'])/(df.loc[end]['Close']))

Answer 2

当您在第for eq in stocks行循环股票时，您将结果保存到eq。所以在每次迭代时它都会被覆盖。您应该将结果存储在列表中，就像我使用data一样。

然后遍历包含数据帧的data列表，然后使用正确的选择。

import numpy as np
import pandas as pd
from pandas_datareader import data as web
from pandas import Series, DataFrame
import datetime
from operator import itemgetter

# edit below for 2 dates you wish to calculate:
start = datetime.datetime(2014, 7, 15)
end = datetime.datetime(2017, 7, 25)

stocks = ('AAPL', 'GOOGL', 'YHOO', 'MSFT', 'AMZN', 'DAI')

# store all the dataframes in a list
data = []

for eq in stocks:
    data.append(web.DataReader(eq, 'google', start, end))

# print required fields from each dataframe
for df in data:
    print (df.ix[start]['Close'])/(df.ix[end]['Close'])

输出：

0.624067042032
0.612014075932
0.613225417599
0.572179539021
0.340850298595
1.28323537643

Answer 3

感谢其他答案，他们都帮了很多忙。这是我最后改进的脚本，感谢您的帮助：

import numpy as np
import pandas as pd
from pandas_datareader import data as web
from pandas import Series, DataFrame
import datetime
from operator import itemgetter

# edit below for 2 dates you wish to calculate:
start = datetime.datetime(2014, 7, 15)
end = datetime.datetime(2017, 7, 25)

stocks = ('AAPL', 'GOOGL', 'YHOO', 'MSFT', 'AMZN', 'DAI')

dict1 = {}

for eq in stocks:
    df = web.DataReader(eq, 'google', start, end)
    k = ((df.loc[start]['Close'])/(df.loc[end]['Close']))
    dict1 [eq] = k

out = sorted(dict1.items(), key=itemgetter(1), reverse = True)

for tick , change in out:
    print (tick,"\t", change)

如何将一些函数应用于列表中的多个代码？（代码改进）

3 个答案:

如何将一些函数应用于列表中的多个代码？ （代码改进）

3 个答案:

如何将一些函数应用于列表中的多个代码？（代码改进）