Question

这是我的代码。

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import quandl

start = pd.to_datetime('2012-01-01')
end = pd.to_datetime('2017-01-01')



aapl = quandl.get('WIKI/aapl.11', start_date = start, end_date= end )
csco = quandl.get('WIKI/csco.11', start_date = start, end_date= end )
ibm = quandl.get('WIKI/ibm.11', start_date = start, end_date= end )
amzn = quandl.get('WIKI/amzn.11', start_date = start, end_date= end )

这将创建4个数据帧。我希望能够通过使用for循环来实现。

这就是我想像的for循环。

for i in [aapl,csco,ibm,amzn]:
    a = 'WIKI/'+ i + '.11'
    i = quandl.get(a, start_date=start, end_date=end)

我希望能够在循环中将数据帧的名称作为字符串引用，以执行其他需要将数据帧的名称作为字符串的功能。

任何人都可以帮助我解决这个问题，或者提出另一种可以达到相同结果的方法。我希望能够以可扩展到100次循环迭代的方式来做到这一点。

谢谢您的帮助。

Answer 1

inames = ['aapl', 'csco', 'ibm', 'amzn']
data = {name: quandl.get('WIKI/'+ name + '.11', start_date=start, end_date=end) for name in inames}

Answer 2

您快到了！您所要做的就是将列表元素括在字符串中。

您现在正在做什么：

a = 'WIKI/'+ i + '.11'                  # Where i is an object, probably a pointer/instance

您需要做什么：

a = 'WIKI/'+ i + '.11'                  # Where i is a good-old-happy string

因此，您的代码中的代码应类似于：

import numpy as np
import pandas as pd


import matplotlib.pyplot as plt
import quandl

start = pd.to_datetime('2012-01-01')
end = pd.to_datetime('2017-01-01')


# You have to add Strings to calculate i (But, you are adding objects)
L = ["aap1", "csco", "ibm", "amzn"]
L_i = []
for i in L:
    a = 'WIKI/'+ i + '.11'
    i = quandl.get(a, start_date=start, end_date=end)
    # Then do whatever you want with the i-s : L_i.append(i)

Answer 3

等同于GB的答案，但如果您不熟悉字典，则无需理解字典。

import pandas as pd
import quandl

start = pd.to_datetime('2012-01-01')
end = pd.to_datetime('2017-01-01')

data = {}

for key in ['aapl', 'csco', 'ibm', 'amzn']:
    name = 'WIKI/'+ key + '.11'
    data[key] = quandl.get(name, start_date=start, end_date=end)

# Then you can use it like
data['aapl'].DoSomething()

如何在for循环中将数据框名称引用为字符串？

3 个答案: